The impact and outcomes of cancer-macrophage fusion.

BACKGROUND: Cancer's hallmark feature is its ability to evolve, leading to metastasis and recurrence. Although genetic mutations and epigenetic changes have been implicated, they don't fully explain the leukocytic traits that many cancers develop. Cell fusion between cancer and somatic cells, particularly macrophages, has been suggested as an alternative pathway for cancer cells to obtain new traits by acquiring exogenous genetic material. METHODS: This study aims to investigate the potential biological outcomes of tumor-myeloid cell fusion by generating tumor-macrophage hybrid cells. Two clones with markedly different tumorigenicity were selected, and RNA-seq was used to compare their RNA expressions with that of the control cells. Based on the results that the hybrid cells showed differential activation in several upstream regulator pathways that impact their biological behaviors, the hybrid cells' abilities to recruit stromal cells and establish angiogenesis as well as their cell cycle distributions were investigated through in vitro and in vivo studies. RESULTS: Although both hybrid clones demonstrated p53 activation and reduced growth rates, they exhibited distinct cell cycle distributions and ability to grow in vivo. Notably, while one clone was highly tumorigenic, the other showed little tumorigenicity. Despite these differences, both hybrid clones were potent environmental modifiers, exhibiting significant abilities to recruit stromal and immune cells and establish angiogenesis. CONCLUSIONS: The study revealed that tumor-somatic cell fusion is a potent environmental modifier that can modulate tumor survival and evolution, despite its relatively low occurrence. These findings suggest that tumor-somatic cell fusion could be a promising target for developing new cancer therapies. Furthermore, this study provides an experimental animal platform to investigate cancer-myeloid fusion and highlights the potential role of tumor-somatic cell fusion in modulating the tumor environment.

Retraction notice to Plexin-B1 and Semaphorin 4D Cooperate to Promote Perineural Invasion in a RhoA/ROK-Dependent Manner Am J Pathol 180 (2012) 1232-1242.

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article is being retracted following correspondence from the Office of Accountability and Compliance at the University of Maryland, Baltimore. An internal investigation into this manuscript by the University of Maryland, Baltimore, found evidence that there are errors with the presentation of the standard deviations and statistical significance shown in Figure 6 which are not supported by the original data, and that these inaccuracies warrant retraction to correct the scientific record. Despite extensive efforts, the journal was unable to contact Dr. Ying-hua Yang and Dr. Hua Zhou with regard to this retraction.

Retraction Note to: The Semaphorin 4D-Plexin-B1-RhoA signaling axis recruits pericytes and regulates vascular permeability through endothelial production of PDGF-B and ANGPTL4.

The Editors-in-Chief have retracted this article [1] following an investigation by the University of Maryland. The institution found that in Figure 1C, the graph showing PDGF-B does not match the original data for the 24-hour time point. The graph shows the value to be over 1000 pg/ml, but the original data have a value of 106.626. In Figure 1F, the data were entered manually to create the standard deviation bars. The data manually entered do not match the original data. When the standard deviations for the original data were calculated, the p values were no longer significant using a paired student t test. In Figure 2C, the original data do not match the published data. In Figure 4B, the images in the first lane and the fifth lane are from the same micrograph (i.e., the same set of conditions). However, the published figure claims that they are different conditions. The metadata in this figure also shows different cell lines than those noted in the article. The first and last images are labelled as "Du145 shAR3 anti AR3.jpg". The second image is labelled as "Du145 shAR8 anti AR8.jpg". The third image is labelled as "Cos1 mARs3 mS3-2 antibody-2.jpg." The fourth image is labelled as "R1 3634 bleed.jpg". Due to these errors, the Editors-in-Chief have found that the results are no longer reliable.

Correction to: Rho-mediated activation of PI(4)P5K and lipid second messengers is necessary for promotion of angiogenesis by Semaphorin 4D.

Figure 3c of this article originally contained standard deviation values which had not been calculated correctly. A single standard deviation value was used for all 5 time points for each condition.

Retraction Note to: Semaphorin 4D cooperates with VEGF to promote angiogenesis and tumor progression.

The Editors-in-Chief have retracted this article [1] following an investigation by the University of Maryland. The institution found that in Figures 1B and 1D, the cell lines are different and all published histograms show SEMA4D mRNA level whereas Excel data have two histograms showing SEMA4D expression and two histograms showing VEGF expression. In Figure 2B, the metadata for one image shows different treatment conditions than those reported in the article. The published image labelled "VEGF + VEGFR-2 shRNA" has a metadata label of S4d-plexinB1 shRNA2". In Figure 2E, statistical significance was shown in the published figure for four comparisons, but upon recalculation, one comparison noted as significant was not. In Figure 6A, the lower left image is labelled "VEGF shRNA" in the published figure, but the metadata label is "S4DshRNA-HN121-20X". In Figure 6C, specifically, within columns 2-4, for each antibody used for immunocytochemistry, the three images have been swapped so that the original images do not match the shRNA labels in the figure (the labels for the two antibodies were correct). In Figure 7D, the first published image is labelled as "IgG" in the paper, but the metadata show a label of "Restore (V+S).tif". The third published image has a label of "anti-VEGF IgG", and the metadata show a label of "con sh.tif". Due to these errors, the Editors-in-Chief have found that the results are no longer reliable.

The use of artificial intelligence, machine learning and deep learning in oncologic histopathology.

BACKGROUND: Recently, there has been a momentous drive to apply advanced artificial intelligence (AI) technologies to diagnostic medicine. The introduction of AI has provided vast new opportunities to improve health care and has introduced a new wave of heightened precision in oncologic pathology. The impact of AI on oncologic pathology has now become apparent, and its use with respect to oral oncology is still in the nascent stage. DISCUSSION: A foundational overview of AI classification systems used in medicine and a review of common terminology used in machine learning and computational pathology will be presented. This paper provides a focused review on the recent advances in AI and deep learning in oncologic histopathology and oral oncology. In addition, specific emphasis on recent studies that have applied these technologies to oral cancer prognostication will also be discussed. CONCLUSION: Machine and deep learning methods designed to enhance prognostication of oral cancer have been proposed with much of the work focused on prediction models on patient survival and locoregional recurrences in patients with oral squamous cell carcinomas (OSCC). Few studies have explored machine learning methods on OSCC digital histopathologic images. It is evident that further research at the whole slide image level is needed and future collaborations with computer scientists may progress the field of oral oncology.

Computer-assisted analysis of immunohistological parameters in oral giant cell granulomas.

OBJECTIVE: The aim of this study was to examine the relationship between active osteoclasts, as defined by positive nuclear NFATc1 signals, and the clinical behaviors of oral giant cell granulomas. MATERIALS AND METHODS: NFATc1 immunohistochemical and TRAP-Cbfa1 double immunofluorescence stainings were performed on 9 cases of peripheral giant cell granulomas (PGCGs), 9 cases of central giant cell granulomas (CGCGs) with a recurrent history, and 10 cases of CGCGs without a recurrent history. The results were photographed and quantified by ImageJ. Nine osteoclast- and osteoblast-related parameters were analyzed with conventional statistics and with Rapidminer, an open data analysis platform for computer predictive modeling. RESULTS: Peripheral giant cell granulomas had a significantly lower percentage of active osteoclasts than CGCGs. The recurrent CGCG subgroup had the highest active osteoclast density in comparison with non-recurrent CGCG subgroup and PCCGs. CONCLUSIONS: The study strongly indicates that the status of osteoclasts, as defined by the subcellular NFATc1 signal, has an association with the clinical behavior of oral giant cell granulomas. NFATc1 staining may be useful as a biomarker to predict recurrence of CGCGs. The study also illustrates the potential application of data science tools in studying pathology to facilitate the discovery of disease-associated biomarkers.

Angiopoietin-2 is expressed in oral Kaposi's sarcoma.

BACKGROUND: Kaposi's sarcoma (KS) persists today as a highly prevalent vascular cancer, often found in HIV patients. Studies have shown that angiopoietin 2 (Ang2), a pro-angiogenic protein, is involved in the pathogenesis of this tumor. However, expression of this protein has not been investigated in oral KS lesions. Thus, we aimed to investigate the expression of Ang2 in samples of oral KS. METHODS: Immunohistochemistry was used to evaluate Ang2 expression in 14 oral KS cases, with degrees of expression being analyzed in a semi-quantitative manner. In addition, clinical information such as age, gender, race, tumor location, size, color, and appearance, as well as HIV status, was collected and included in the analysis. RESULTS: All patients were white males, mostly HIV-positive, with a mean age of 40 years. Clinically, the lesions were dark red/blue/purple masses, ranging from 1 to 2.5 cm in diameter, found in various locations such as the tongue, palate, and gingiva. Expression of Ang2 was noted in 72% (10/14) of the samples. Of these, 10% showed weak expression, 60% moderate, and 30% strong expression. CONCLUSIONS: Our results indicate that Ang2 is expressed in oral KS and, consistent with results from previous studies, show that Ang2 may contribute to the pathogenesis of this lesion.

Emergent gingival cyst of the adult.

The gingival cyst of the adult is a relatively rare, benign odontogenic cyst that maintains an insidious growth rate. This article describes a case of a diminutive fibrotic overgrowth arising on the labial interproximal gingiva between the mandibular right canine and first premolar in a 68-year-old woman. Within 1 year, the lesion had increased in size and appeared vesicular. The morphologic changes warranted surgical excision and histopathologic review. The lesion was diagnosed as a gingival cyst. At a 4.5-month recall appointment, there was no evidence of recurrence. Early lesional detection can potentially mitigate mucogingival defects and improve clinical outcomes.

Superficial Mucocele of the Ventral Tongue: Presentation of a Rare Case and Literature Review.

The superficial mucocele is a rare variant of the common mucocele and noted microscopically by subepithelial pools of mucin. To increase the understanding of oral superficial mucoceles, a database was created from the demographics of case reports and case series from a PubMed search. At least 200 patients with superficial mucoceles have been described in the English-language literature, 82 of whom had biopsy-proven lesions; additional clinical information was available for 39 of these 82 patients. Compiled data suggest superficial mucoceles offered phenotypic distinctions from the common mucocele because they were more apt to occur in middle-aged women, often on the soft palate and buccal mucosa. Affected patients frequently had multiple lesions that were smaller than 3 mm and nearly 50% of patients developed recurrence. This report also describes the first histopathologically confirmed case of a superficial mucocele arising on the ventral tongue in a 22-year-old man. It is speculated that the glossal lesion might have developed from long-term impingement from exposed metal barbs from an orthodontic splint. Persistent lesions or atypical presentations underscore the need for histopathologic examination.

The Semaphorin 4D-Plexin-B1-RhoA signaling axis recruits pericytes and regulates vascular permeability through endothelial production of PDGF-B and ANGPTL4.

Semaphorin 4D (SEMA4D) is a member of a family of transmembrane and secreted proteins that have been shown to act through its receptor Plexin-B1 to regulate axon growth cone guidance, lymphocyte activation, and bone density. SEMA4D is also overexpressed by some malignancies and plays a role in tumor-induced angiogenesis similar to vascular endothelial growth factor (VEGF), a protein that has been targeted as part of some cancer therapies. In an attempt to examine the different effects on tumor growth and vascularity for these two pro-angiogenic factors, we previously noted that while inhibition of both VEGF and SEMA4D restricted tumor vascularity and size, vessels forming under conditions of VEGF blockade retained their association with pericytes while those arising in a background of SEMA4D/Plexin-B1 deficiency did not, an intriguing finding considering that alteration in pericyte association with endothelial cells is an emerging aspect of anti-angiogenic intervention in the treatment of cancer. Here we show through array analysis, immunoblots, migration and co-culture assays and VE-cadherin immunohistochemistry that SEMA4D production by head and neck carcinoma tumor cells induces expression of platelet-derived growth factor-B and angiopoietin-like protein 4 from endothelial cells in a Plexin-B1/Rho-dependent manner, thereby influencing proliferation and differentiation of pericytes and vascular permeability, whereas VEGF lacks these effects. These results partly explain the differences observed between SEMA4D and VEGF in pathological angiogenesis and suggest that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of solid tumors.

Plexin-B1 and semaphorin 4D cooperate to promote perineural invasion in a RhoA/ROK-dependent manner.

Perineural invasion (PNI) is a tropism of tumor cells for nerve bundles located in the surrounding stroma. It is a pathological feature observed in certain tumors, referred to as neurotropic malignancies, that severely limits the ability to establish local control of disease and results in pain, recurrent growth, and distant metastases. Despite the importance of PNI as a prognostic indicator, its biological mechanisms are poorly understood. The semaphorins and their receptors, the plexins, compose a family of proteins originally shown to be important in nerve cell adhesion, axon migration, and proper central nervous system development. Emerging evidence has demonstrated that these factors are expressed in tissues outside of the nervous system and represent a widespread signal transduction system that is involved in the regulation of motility and adhesion in different cell types. We believe that the plexins and semaphorins, which are strongly expressed in both axons and many carcinomas, play a role in PNI. In this study, we show that plexin-B1 is overexpressed in tissues and cell lines from neurotropic malignancies and is attracted to nerves that express its ligand, semaphorin 4D, in a Rho/Rho kinase-dependent manner. We also demonstrate that nerves are attracted to tumors through this same system of proteins, suggesting that both plexin-B1 and semaphorin 4D are important in the promotion of PNI.

Differential expression of organic cation transporter OCT-3 in oral premalignant and malignant lesions: potential implications in the antineoplastic effects of metformin.

BACKGROUND: Recent evidence indicates that metformin, a biguanide used as first-line treatment for type 2 diabetes, prevents the conversion of carcinogen-induced oral dysplasias into head and neck squamous cell carcinomas (HNSCC), most likely by inhibiting mammalian target of rapamycin complex 1 (mTORC1) oncogenic signaling. Whether metformin acts directly at the primary tumor site or indirectly by modulating hormonal secretion from extratumoral organs remains unknown. As organic cation transporters (OCT) belonging to the solute carrier 22A gene family, including OCT-1, OCT-2, and OCT-3, mediate metformin uptake and activity, it is critical to define what role they play in the antineoplastic activity of metformin. METHODS: Immunohistochemical and immunoblotting techniques were used in normal, dysplastic and HNSCC tissues, and HNSCC cell lines, respectively, to determine OCTs expression levels. RESULTS: We report that only OCT-3 was highly expressed in a number of HNSCC cell lines, oral epithelial dysplasias, and well to moderately differentiated HNSCC. Indeed, inhibition of OCT-3 expression and activity in HNSCC cells prevented metformin-induced AMP-activated protein kinase activation and mTORC1 pathway inhibition. Moreover, in oral dysplasias, high OCT-3 expression localized to epithelial compartments where mTORC1 signaling was also upregulated suggestive of a potential local effect of metformin. CONCLUSIONS: The concept of using metformin as a chemopreventive agent to control head and neck carcinogenesis is promising. Further work is warranted to elucidate largely unexplored mechanisms of metformin uptake and pharmacologic action that may ultimately influence the selection of the most suitable patients who can benefit from metformin in head and neck cancer chemoprevention.

The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma.

Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors.

Viral G protein-coupled receptor up-regulates Angiopoietin-like 4 promoting angiogenesis and vascular permeability in Kaposi's sarcoma.

Kaposi's sarcoma (KS) is an enigmatic vascular tumor thought to be a consequence of dysregulated expression of the human herpesvirus-8 (HHV-8 or KSHV)-encoded G protein-coupled receptor (vGPCR). Indeed, transgenic animals expressing vGPCR manifest vascular tumors histologically identical to human KS, with expression of the viral receptor limited to a few cells, suggestive of a paracrine mechanism for vGPCR tumorigenesis. Both human and vGPCR experimental KS lesions are characterized by prominent angiogenesis and vascular permeability attributed to the release of angiogenic molecules, most notably vascular endothelial growth factor. However, the relative contribution of these paracrine mediators to the angiogenic and exudative phenotype of KS lesions remains unclear. Here we show that vGPCR up-regulation of Angiopoietin-like 4 (ANGPTL4) plays a prominent role in promoting the angiogenesis and vessel permeability observed in KS. Indeed, ANGPTL4 expression is a hallmark of vGPCR experimental and human KS lesions. Inhibition of ANGPTL4 effectively blocks vGPCR promotion of the angiogenic switch and vascular leakage in vitro and tumorigenesis in vivo. These observations suggest that ANGPTL4 is a previously unrecognized target for the treatment of patients with KS. As angiogenesis and increased vessel permeability are common themes in all solid tumors, these findings may have a broad impact on our understanding and treatment of cancer.

Recurrent peripheral odontogenic keratocyst: Review of the literature and presentation of a novel case initially masquerading as an atypical infected lateral periodontal cyst.

AIM: To review published cases and case series of the peripheral odontogenic keratocyst (POKC) of the gingiva, report an unusual presentation, and discuss lesional recurrence. MATERIALS AND METHODS: A search of the English language literature for gingival OKCs was conducted. The inclusion of new case yielded a database containing 29 affected patients. Clinical, surgical, radiographic, and histopathologic findings have been summarized. RESULTS: With available patient demographics, 62.5% were female and 37.5% were male, with an overall mean age at diagnosis of 53.8 years. There was near-equal lesional affinity for the jaws, of which 44.0% occurred in the posterior region, 32.0% anteriorly, and 24.0% overlapped these areas. Twenty-five percent of lesions had a normal color, 30.0% appeared yellow, 20.0% were white, and 10.0% were blue. The majority of lesions were < 1 cm and nearly 42% manifested exudation or fluctuance. Lesional pain was infrequent. Pressure resorption was recorded in 45.8% of cases. Most lesions were managed with conservative surgical modalities. Follow-up information was available in 16 primary cases, of which 5 recurred, signifying a 31.3% recurrence rate, including the featured case, which recurred twice. CONCLUSION: To reduce recurrence of a gingival OKC, supraperiosteal dissection is advocated. Further, it is advised to follow POKCs for 5-7 years postoperatively, remaining vigilant for subtle clinical manifestations of recurrence. Timely discovery and excision of a POKC of the gingiva may decrease the incidence of a mucogingival defect.

Semaphorin 4D cooperates with VEGF to promote angiogenesis and tumor progression.

The semaphorins and plexins comprise a family of cysteine-rich proteins implicated in control of nerve growth and development and regulation of the immune response. Our group and others have found that Semaphorin 4D (SEMA4D) and its receptor, Plexin-B1, play an important role in tumor-induced angiogenesis, with some neoplasms producing SEMA4D in a manner analogous to vascular endothelial growth factor (VEGF) in order to attract Plexin-B1-expressing endothelial cells into the tumor for the purpose of promoting growth and vascularity. While anti-VEGF strategies have been the focus of most angiogenesis inhibition research, such treatment can lead to upregulation of pro-angiogenic factors that can compensate for the loss of VEGF, eventually leading to failure of therapy. Here, we demonstrate that SEMA4D cooperates with VEGF to promote angiogenesis in malignancies and can perform the same function in a setting of VEGF blockade. We also show the potential value of inhibiting SEMA4D/Plexin-B1 signaling as a complementary mechanism to anti-VEGF treatment, particularly in VEGF inhibitor-resistant tumors, suggesting that this may represent a novel treatment for some cancers.

Ghost Cell Odontogenic Carcinoma Arising in a Previous Calcifying Odontogenic Cyst: A Case Report and Review of Literature.

Ghost cell odontogenic carcinoma (GCOC) is a rare malignant tumor of odontogenic origin, with only about 50 cases reported in the English literature so far. Histologically, it is characterized by ghost cells, dentinoid deposits, high grade malignant cellular features, and areas of necrosis and invasion. Having common histological features with other odontogenic ghost cell lesions (OGCL) like calcifying odontogenic cyst (COC) and dentinogenic ghost cell tumors, it is crucial to recognize GCOC malignant features, as it can be destructive and invasive, sometimes showing distant metastases and high recurrence rate. For this reason, it may entail more aggressive surgical approach and multimodal therapeutic regimen. Here we present a case report of GCOC arising in a previous COC, treated with surgical excision that showed persistence and recurrence after two years. The clinical and histological features of this rare occurrence are presented, in addition to the surgical approach, and a summary of literature review of OGCL.

Rho-mediated activation of PI(4)P5K and lipid second messengers is necessary for promotion of angiogenesis by Semaphorin 4D.

Phosphatidylinositol 4-phosphate 5-kinase (PI(4)P5K) is a type I lipid kinase that generates the lipid second messenger phospholipid phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2) and functions downstream of RhoA in actin organization. It is known to play an essential role in neurite remodeling, yielding a phenotype identical to that seen in cells treated with Semaphorin 4D (Sema4D), a protein that regulates proliferation, adhesion and migration in many different cell types. Plexin-B1, the receptor for Sema4D, activates RhoA in order to generate a pro-angiogenic signal in endothelial cells. Therefore, we looked in human umbilical vein endothelial cells (HUVEC) to determine if Plexin-B1 exerted control over the cytoskeleton by regulation of PI(4)P5K activity. Here we demonstrate the Rho/Rho Kinase (ROK)-dependent generation of PI(4,5)P(2) upon treatment of HUVEC with Sema4D, as well as co-localization of PI(4)P5Kα with Plexin-B1. Formation of PI(4,5)P(2) was necessary for cytoskeletal polymerization, as expression of the phosphatase synaptojanin blocked this effect. We noted phosphorylation and activation of PLCγ and an increase in intracellular calcium upon treatment of HUVEC with Sema4D, responses that were necessary for a pro-angiogenic phenotype observed in vitro. Taken together, these results suggest that Plexin-B1 promotes angiogenesis in endothelial cells by signaling through PI(4)P5Kα and generating lipid second messengers.

Immunohistochemical profile of the anti-apoptosis, apoptosis and proliferation markers Bcl-2, caspase-3, p53, and Ki-67 in botryoid odontogenic cysts compared to lateral periodontal cysts and gingival cysts of the adult.

We investigated the differences in growth and rates of recurrence of the botryoid odontogenic cyst (BOC) and the less aggressive lateral periodontal cyst (LPC) and gingival cyst of the adult (GCA). We compared the immunohistochemical expression of selected biomarkers of apoptosis and proliferation and of regulators of their activity. Sections from archival paraffin blocks of 15 BOCs, six GCAs, six LPCs, and three odontogenic keratocysts (OKCs) were processed for immunohistochemical localization of Bcl-2, caspase-3, p53 and Ki-67. Labeled and unlabeled epithelial cells were counted and differences in the mean labeling index (LI) were evaluated statistically. The only significant differences in LI were for the anti-apoptotic marker, Bcl-2; the hierarchy was BOC > OKC > LPC > GCA. In two BOCs, 97% of the cells, and in all OKCs, all of the basal cells were labeled with Bcl-2. Otherwise, cells labeled with Bcl-2, p53 and caspase-3 were scattered among the basal and intermediate epithelial cell layers. Ki-67 labeled almost exclusively basal cells in the BOCs, LPCs and GCAs, and both basal and intermediate layer cells in the OKCs. Our findings suggest that while there was no significant difference in replicative potential of the GCAs, LPCs and BOCs, factors that influence apoptosis may be partially responsible for the more aggressive behavior of BOCs and OKCs.