Intestinal strictures in Crohn's disease: An update from 2023.

Crohn's disease (CD) is a chronic inflammatory disease that leads to intestinal stricture in nearly 35% of cases within 10 years of initial diagnosis. The unknown pathogenesis, lack of universally accepted criteria, and absence of an effective management approach remain unconquered challenges in structuring CD. The pathogenesis of stricturing CD involves intricate interactions between factors such as immune cell dysbiosis, fibroblast activation, and microecology imbalance. New techniques such as single-cell sequencing provide a fresh perspective. Non-invasive diagnostic tools such as serum biomarkers and novel cross-sectional imaging techniques offer a precise understanding of intestinal fibrostenosis. Here, we provide a timely and comprehensive review of the worthy advancements in intestinal strictures in 2023, aiming to dispense cutting-edge information regarding fibrosis and to build a cornerstone for researchers and clinicians to make greater progress in the field of intestinal strictures.

Bowel Stiffness Assessed by Shear-Wave Ultrasound Elastography Predicts Disease Behavior Progression in Patients With Crohn's Disease.

INTRODUCTION: There is a lack of reliable predictors of disease behavior progression in patients with Crohn's disease (CD). Real-time shear-wave elastography (SWE) is a novel method for evaluating tissue stiffness. However, its value for assessing CD has not yet been investigated. We aimed to explore the value of SWE and other ultrasound parameters at diagnosis in predicting CD behavior progression. METHODS: We retrospectively collected data from patients with CD with the nonstenotic nonpenetrating disease (B1 phenotype based on the Montreal classification). All patients underwent intestinal ultrasound at baseline and were followed up. The end point was defined as disease behavior progression to stricturing (B2) or penetrating (B3) disease. Cox regression analysis was performed for the association between baseline characteristics and subsequent end points. In addition, a multivariate nomogram was established to predict the risk of disease behavior progression quantitatively. RESULTS: A total of 130 patients with CD with B1 phenotype were enrolled. Twenty-seven patients (20.8%) developed B2 or B3 disease, with a median follow-up of 33 months. Multivariate analysis identified that SWE was the only independent predictor of disease behavior progression (hazard ratio 1.08, 95% confidence interval 1.03-1.12, P = 0.001). A reverse of the HR appeared at the cutoff 12.75 kPa. The nomogram incorporating SWE and other clinical characteristics showed a good prediction performance (area under the curve = 0.792). DISCUSSION: Intestinal stiffness assessed using SWE is an independent predictor of disease behavior progression in patients with CD. Patients with CD with SWE >12.75 kPa at diagnosis are prone to progress toward stricturing or penetrating diseases.

Predicting Factors of Long-term Outcome of Gastrointestinal Behçet's Disease: A Chinese Retrospective Study.

PURPOSE: Behçet's disease (BD) is a complex disorder affecting multiple systems and organs, and gastrointestinal BD is poorly understood. We aimed to identify factors influencing the long-term outcomes of patients with gastrointestinal BD. METHODS: Consecutive patients with gastrointestinal BD were analyzed retrospectively. Data on the following clinical characteristics were collected: sex, age at diagnosis, symptoms, endoscopic findings, medical treatments, and surgery. Mucosal healing and surgical rates at 1, 2, and 5 years were evaluated. Log-rank test and Cox proportional hazards regression models were used to evaluate the factors affecting long-term outcomes. FINDINGS: Baseline data of 175 patients with gastrointestinal BD were included. The mean (SD) age at diagnosis was 38.3 (12.9) years. The typical clinical symptoms were oral ulcer (72.6%), abdominal pain (71.4%), and weight loss (41.1%). The most commonly involved location was the ileocecum; isolated oval ulcer was the most common ulcer type. Seventeen patients (9.7%) underwent 18 surgeries after inclusion. The cumulative surgical rates were 8.6% (n/N = 15/175), 8.6% (n/N = 15/175), and 9.1% (n/N = 16/175) in 1, 2, and 5 years, respectively. Data from 101 patients who underwent at least 2 endoscopies were included in the analysis for mucosal healing. Kaplan-Meier curve showed that the cumulative mucosal healing rates at 1, 2, and 5 years were 34.7% (n/N = 35/101), 41.6% (n/N = 42/101), and 61.4% (n/N = 62/101), respectively. We compared cumulative mucosal healing rates between 4 treatment groups, including 5-aminosalicylic acid (3% [n/N = 3/101]), mono-immunosuppressant (31.7% [n/N = 32/101]), combined therapy (36.6% [n/N = 37/101]), and escalation therapy (28.7% [n/N = 29/101]), and found that mono-immunosuppressant achieved earlier mucosal healing than combined therapy (P = 0.0008) and escalation therapy (P = 0.0008). The univariate analysis showed that moderate to severe disease activity (P = 0.013, P = 0.004), diameter of the maximal ulcer >4 cm (P = 0.002), and nonsimple esophageal involvement (P < 0.001) were risk factors, and number of ulcers between 2 and 5 was the protective factor of mucosal healing (P = 0.001). Multivariate regression analysis indicated that nonsimple esophageal involvement (P < 0.001) and the maximal ulcer >4 cm (P = 0.041) were independent risk factors of mucosal healing. IMPLICATIONS: Most patients with gastrointestinal BD need long-term treatment to achieve mucosal healing. The location and size of ulcers have a significant impact on the mucosal healing of gastrointestinal BD.

Establishment and validation of a risk assessment model for myopia among Chinese primary school students during the COVID-19 pandemic: A lasso regression approach.

Purpose: To construct a risk assessment model for forecasting the likelihood of myopia in elementary school students. Design: A cross-sectional study. Methods: This study utilized convenient sampling and questionnaire survey to collect data from eligible elementary students and their parents during the coronavirus disease 2019 (COVID-19) pandemic period from March to December 2020. The data were divided into training and testing sets in a 7:3 ratio. Lasso regression was employed to screen variables for inclusion in the model to establish a generalized linear model, with a nomogram model as the final result. Results: The study included 1139 elementary students, comprising 54.5 % male and 45.5 % female participants. A total of 37 variables were obtained, which were analyzed using lasso regression. Cross-validation revealed that the best lambda value was 0.04201788. Five variables affecting myopia were identified: three risk and two protective factors. The three risk factors were student age (OR = 1.32), family location (urban vs. rural, OR = 2.33), and parents' occupation (compared with farmer: worker, OR = 2.03; teacher, OR = 1.62; medical worker, OR = 5.64; self-employed, OR = 1.78; civil servant, OR = 1.65; company employee, OR = 1.45; service industries, OR = 3.38; and others, OR = 3.20). The two protective factors were eye distance score (OR = 0.83) and eye health exercise score (OR = 0.95). The model was verified and showed good accuracy with an AUC of 0.778 and Brier score of 0.122 in addition to satisfactory clinical effects. Conclusions: The model effectively predicted the risk of myopia in elementary school students during the COVID-19 pandemic. Using this model, high-risk groups can be identified to provide a foundation for early intervention and follow-up, thereby reducing the incidence of myopia in this population.

Corrigendum: Discovery of spirooxindole-derived small-molecule compounds as novel HDAC/MDM2 dual inhibitors and investigation of their anticancer activity.

[This corrects the article DOI: 10.3389/fonc.2022.972372.].

A nomogram incorporating ileal and anastomotic lesions separately to predict the long-term outcome of Crohn's disease after ileocolonic resection.

Background: The Rutgeerts score (RS) is widely used to predict postoperative recurrence after ileocolonic resection for Crohn's disease (CD) based on the severity of lesions at the neoterminal ileum and anastomosis (RS i0-i4). However, the value of anastomotic ulcers remains controversial. Objectives: Our aim was to establish a nomogram model incorporating ileal and anastomotic lesions separately to predict the long-term outcomes of CD after ileal or ileocolonic resection. Design: A total of 136 patients with CD were included in this retrospective cohort study. Methods: Consecutive CD patients who underwent ileal or ileocolonic resections with postoperative ileocolonoscopy evaluation within 1 year after the surgery were included. The primary endpoint was postoperative clinical relapse (CR). An endoscopic classification separating ileal and anastomotic lesions was applied (Ix for neoterminal ileum lesions; Ax for anastomotic lesions). A nomogram was constructed to predict CR. The performance of the model was evaluated by the receiver-operating characteristic (ROC) curve and decision curve analysis (DCA). Results: CR was observed in 47.1% (n = 64) of patients within a median follow-up of 26.9 (interquartile range, 11.4-55.2) months. The risk of CR was significantly higher in patients with an RS ⩾ i2 assessed by the first postoperative endoscopy compared with patients with an RS ⩽ i1 (p < 0.001). Moreover, the cumulative rate of CR was significantly higher in patients with ileal lesions (I1-4) compared with patients without (I0) (p < 0.001). Besides, patients with anastomotic lesions (A1-3) had significantly higher rates of CR than patients without (A0) (p = 0.002). A nomogram, incorporating scores of postoperative ileal or anastomotic lesions, sex, L2-subtype and perianal disease, was established. The DCA analysis indicated that the nomogram had a higher benefit for CR, especially at the timeframe of 24-60 months after index endoscopy, compared to the traditional RS score. Conclusion: A nomogram incorporating postoperative ileal and anastomotic lesions separately was developed to predict CR in CD patients, which may serve as a practical tool to identify high-risk patients who need timely postoperative intervention.

Lymphatic endothelial transcription factor Tbx1 promotes an immunosuppressive microenvironment to facilitate post-myocardial infarction repair.

The heart is an autoimmune-prone organ. It is crucial for the heart to keep injury-induced autoimmunity in check to avoid autoimmune-mediated inflammatory disease. However, little is known about how injury-induced autoimmunity is constrained in hearts. Here, we reveal an unknown intramyocardial immunosuppressive program driven by Tbx1, a DiGeorge syndrome disease gene that encodes a T-box transcription factor (TF). We found induced profound lymphangiogenic and immunomodulatory gene expression changes in lymphatic endothelial cells (LECs) after myocardial infarction (MI). The activated LECs penetrated the infarcted area and functioned as intramyocardial immune hubs to increase the numbers of tolerogenic dendritic cells (tDCs) and regulatory T (Treg) cells through the chemokine Ccl21 and integrin Icam1, thereby inhibiting the expansion of autoreactive CD8+ T cells and promoting reparative macrophage expansion to facilitate post-MI repair. Mimicking its timing and implementation may be an additional approach to treating autoimmunity-mediated cardiac diseases.

A Novel Serum Metabolomic Panel for the Diagnosis of Crohn's Disease.

BACKGROUND: A distinctive metabolic phenotype provides the opportunity to discover noninvasive biomarkers for the diagnosis of Crohn's disease (CD) and for differentiating it from other intestinal inflammatory diseases. The study sought to identify new biomarkers for CD diagnosis. METHODS: Serum metabolites from 68 newly diagnosed and treatment-naïve patients with CD and 56 healthy control (HC) subjects were profiled using targeted liquid chromatography-mass spectrometry. Five metabolic biomarkers were identified to distinguish patients with CD from the HC subjects and validated in a separate cohort consisting of 110 patients with CD and 90 HC subjects using a combination of univariate analysis, orthogonal partial least-squares discriminant analysis, and receiver-operating characteristic curve analysis. Differences in the 5 metabolites were evaluated among patients with CD and patients with ulcerative colitis (n = 62), intestinal tuberculosis (n = 48), and Behçet's disease (n = 31). RESULTS: Among the 185 quantified metabolites, a panel of 5 (pyruvate, phenylacetylglutamine, isolithocholic acid, taurodeoxycholic acid, and glycolithocholic acid) were found to distinguish patients with CD with high accuracy from HC subjects, with an area under the curve of 0.861 (P < .001). The performance of the model in assessing clinical disease activity was comparable to that of the present biomarkers: C-reactive protein and erythrocyte sedimentation rate. The 5 metabolites were significantly different among the patients and were valuable in the differentiation between CD and other chronic intestinal inflammatory diseases. CONCLUSIONS: The combination of 5 serum metabolite biomarkers for the diagnosis of CD has the potential to provide an accurate, noninvasive, and inexpensive alternative to conventional tests and might be valuable for the differentiation from other diagnostically challenging intestinal inflammatory diseases.

Serum metabolomic analysis was performed on patients with Crohn's disease and healthy control subjects, which discovered 5 metabolites as a novel serum metabolomic panel. These metabolites were further validated in a second patient cohort and a third differentiation cohort. The data showed that these metabolites were valuable in diagnosis of Crohn's disease and for differentiating it from other intestinal inflammatory diseases.

Matrix stiffening facilitates the collective invasion of breast cancer through the periostin-integrin mechanotransduction pathway.

Matrix rigidity is a critical contributor to tumor progression; however, whether and how matrix stiffness modulates the collective invasion of tumor cells remain unknown. Here we demonstrate that increased matrix stiffness activates YAP to promote the secretion of periostin (POSTN) in cancer-associated fibroblasts, which in turn augments the matrix rigidity of mammary glands and breast tumor tissues by facilitating collagen crosslinking. Moreover, decreased tissue stiffening resulted from the POSTN deficiency impairs peritoneal metastatic potential of orthotopic breast tumors. Increased matrix stiffness also promotes three-dimensional (3D) collective breast tumor cell invasion via multicellular cytoskeleton remodeling. POSTN triggers the integrin/FAK/ERK/Cdc42/Rac1 mechanotransduction pathway during 3D collective invasion of breast tumor. Clinically, high POSTN expression correlates with high collagen levels in breast tumors and cooperatively determines the metastatic recurrence potential in breast cancer patients. Collectively, these findings indicate that matrix rigidity promotes 3D collective invasion of breast tumor cells via the YAP-POSTN-integrin mechanotransduction signaling.

Current situation and influencing factors of disease uncertainty in parents of children with Sturge‒Weber syndrome: a retrospective study.

BACKGROUND: Sturge Weber syndrome (SWS), can cause extensive capillary malformations on the face, head, trunk, and other parts of the body, and the eyes can also suffer optic nerve injury. Secondary glaucoma can cause blindness, which has the characteristics of a relatively hidden onset and unclear pathogenesis. The treatment of SWS secondary glaucoma has always been difficult, and due to the characteristics of the disease, there is uncertainty about the long-term efficacy and safety of various treatment methods for such patients. METHODS: A total of 105 parents of children with SWS completed a self-designed general information questionnaire, a generalized anxiety questionnaire (GAD-7), a patient health questionnaire (PHQ-2), a stress perception scale (PSS-4), a simple coping scale (SCSQ) and a disease-uncertainty scale (PPUS). RESULTS: The total uncertainty score of parents of children with SWS was 79.07 ± 13.24, and the average item score was 2.82 ± 0.47. Multiple linear regression analysis revealed that anxiety and simple coping were the main influencing factors of disease uncertainty among parents of children with SWS (P < 0.05). CONCLUSIONS: Parents of children with SWS exhibit a high level of disease uncertainty. Medical staff should pay attention to the source of parents' disease uncertainty and provide targeted interventions, which are of great importance in reducing parents' disease uncertainty.

The Role of Colchicine in Different Clinical Phenotypes of Behcet Disease.

PURPOSE: Behcet disease (BD) is a multisystemic disorder characterized by variable clinical manifestations that affect nearly all systems and organs. Colchicine, an alkaloid plant extract, is considered as the first-line therapy for gout, pericarditis, and familial Mediterranean fever. However, the role of colchicine in the treatment of different clinical phenotypes of BD has not been clearly described. This narrative review summarizes the clinical use of colchicine in BD. METHODS: All relevant literature from 1980 to March 2021 was searched in PubMed, MEDLINE, and Cochrane Library. The Medical Subject Heading terms and related words that were searched are as follows: Behcet's disease, Behcet's syndrome, BD, colchicine, management, treatment, and therapy. FINDINGS: BD is an autoimmune systemic vasculitis with various clinical phenotypes, with involvement of skin mucosa, joints, eyes, and gastrointestinal, vascular, and neurologic systems. Colchicine has been used for centuries, acts by binding to tubulin to prevent the mitotic process, and has anti-inflammatory, antitumor, and antifibrotic properties. Colchicine has been reported to be an effective option for the treatment of skin, mucosal, and joint involvement in patients with certain BD clinical phenotypes. IMPLICATIONS: Colchicine reduces the severity of certain clinical phenotypes and may improve the overall disease activity index in patients with BD. More randomized clinical trials are needed to confirm the value of colchicine in the treatment of BD, and further elucidation of the mechanisms is also needed, which may reveal new application of colchicine that has been used for centuries.

Effects of SENP1-induced deSUMOylation of STAT1 on proliferation and invasion in nasopharyngeal carcinoma.

Nasopharyngeal carcinoma (NPC) is the most common nasopharyngeal squamous cell carcinoma, and recurrence and metastasis are still difficult problems in its current treatment. This study aimed to investigate the effect of SUMO modification of STAT1 protein on the proliferation and invasion of NPC, and to reveal the underlying mechanism. Two gene expression profiles (GSE12452 and GSE53819) of 49 nasopharyngeal carcinomas and 28 normal controls were analyzed to identify differentially expressed genes. In total, 448 up-regulated genes and 622 down-regulated genes were identified. In addition, 16 SUMO-related molecules in the NPC dataset GSE102349 with survival data were analyzed, and it was found that the high expression of SENP1 and SENP2 was closely related to the poor prognosis of NPC. GO and GSEA analysis suggested that immune-related biological processes, IFN-γ-STAT signaling pathway and protein modification-related molecules were significantly enriched in NPC, resulting in poor survival prognosis. In order to verify the results of bioinformatics analysis and explore its underlying molecular mechanisms, western blot, Immunofluorescence, Immunoprecipitation and Immunohistochemistry are conducted in NPC cells, animals and clinical samples. SENP1 and STAT protein levels were increased in NPC tissues. SENP1 inhibited SUMOylation of STAT1, thereby promoting the protein level of STAT1 and the nuclear translocation. SENP1 promoted the proliferation and invasion of NPC by inducing STAT1. Overall, SENP1-induced deSUMOylation of STAT1, resulting in an increased proliferation and invasion of nasopharyngeal carcinoma.

Anemia as a risk factor for restenosis in femoropopliteal arterial disease after drug-coated balloon angioplasty.

OBJECTIVE: This study aimed to investigate the relationship between anemia and restenosis in patients with femoropopliteal arterial disease following drug-coated balloon (DCB) angioplasty. METHODS: 194 patients treated with DCB for femoropopliteal lesions were retrospectively analyzed for up to 12 months of follow-up between January 2017 and September 2020. Baseline clinical and procedural characteristics were compared between the anemia and non-anemia patients, and predictors of restenosis were identified using logistic regression. RESULTS: 32.5% of the patients undergoing DCB angioplasty had anemia. Patients with anemia were significantly older, with higher rates of hypertension, coronary artery disease, chronic renal insufficiency, and diabetes, and with lower rates of smoking and male gender. In the multivariate analysis, anemia was independently and significantly associated with a higher risk of restenosis (OR, 3.872; 95% CI, 1.556-9.638; P = 0.004). CONCLUSION: Anemia is independently associated with restenosis in patients treated with DCB for femoropopliteal arterial disease. Patients with lower baseline hemoglobin might have more chances to develop restenosis at follow-up.

Current practice, attitude and views of providing pregnancy care for women with type 1 diabetes in China: a qualitative study.

OBJECTIVE: Data are sparse on healthcare needs related to pregnancy among Chinese women with type 1 diabetes (T1D) or the gap between the needs and healthcare provision in China. We aimed to identify their needs and the gaps in pregnancy care provision. DESIGN: This is a qualitative, face-to-face, one-to-one in-depth interview study. We recruited our participants using a purposive sampling strategy. Semistructural outlines were used to guide the interviews. The interviews were digitally recorded, transcribed and analysed using a thematic framework method with NVivo V.10.0. SETTING: Guangdong Province in China. PARTICIPANTS: This study involved three key stakeholders of pregnancy care for women with T1D: 29 women with T1D of childbearing age (aged 18-50 years), 16 family members (husbands, parents and parents-in-law of women with T1D) and 35 relevant healthcare providers (HCPs). RESULTS: We found that women with T1D and the family members had a more pessimistic attitude towards pregnancy outcomes, which was different from the more positive view of HCPs. However, all three stakeholders shared the following perspectives regarding pregnancy-related care for women with T1D: (1) lack of knowledge and access to education, (2) lack of multidisciplinary cooperation, (3) education should be started earlier in adulthood, (3) positive role of peer support, and (4) hope for future training of HCPs for relevant knowledge and skills specified for T1D and pregnancy with T1D. CONCLUSIONS: An immense gap was identified between the needs of women with T1D regarding pregnancy-related care and current care provision in China. These findings suggest that education be provided to patients and HCPs, and the role of professional and multidisciplinary support should be enhanced to optimise pregnancy care for women with T1D in China.

Fibrosis in fat: From other diseases to Crohn's disease.

Creeping fat is a specific feature of Crohn's disease (CD) and is characterized by mesenteric fat wrapping around the intestine. It highly correlates with intestinal transmural inflammation, muscular hypertrophy, fibrosis, and stricture formation. However, the pathogenesis of creeping fat remains unclear. Molecular crosstalk exists between mesenteric fat and the intestine. Indeed, creeping fat contains different types of cells, including adipocytes and immune cells. These cell types can produce various cytokines, fatty acids, and growth factors, which affect the mesenteric fat function and modulate intestinal inflammation and immunity. Moreover, adipocyte progenitors can produce extracellular matrix to adapt to fat expansion. Previous studies have shown that fat fibrosis is an important feature of adipose tissue malfunction and exists in other diseases, including metabolic disorders, cancer, atrial fibrillation, and osteoarthritis. Furthermore, histological sections of CD showed fibrosis in the creeping fat. However, the role of fibrosis in the mesenteric fat of CD is not well understood. In this review, we summarized the possible mechanisms of fat fibrosis and its impact on other diseases. More specifically, we illustrated the role of various cells (adipocyte progenitors, macrophages, mast cells, and group 1 innate lymphoid cells) and molecules (including hypoxia-inducible factor 1-alpha, transforming growth factor-beta, platelet-derived growth factor, and peroxisome proliferator-activated receptor-gamma) in the pathogenesis of fat fibrosis in other diseases to understand the role of creeping fat fibrosis in CD pathogenesis. Future research will provide key information to decipher the role of fat fibrosis in creeping fat formation and intestinal damage, thereby helping us identify novel targets for the diagnosis and treatment of CD.

Discovery of spirooxindole-derived small-molecule compounds as novel HDAC/MDM2 dual inhibitors and investigation of their anticancer activity.

Simultaneous inhibition of more than one target is considered to be a novel strategy in cancer therapy. Owing to the importance of histone deacetylases (HDACs) and p53-murine double minute 2 (MDM2) interaction in tumor development and their synergistic effects, a series of MDM2/HDAC bifunctional small-molecule inhibitors were rationally designed and synthesized by incorporating an HDAC pharmacophore into spirooxindole skeletons. These compounds exhibited good inhibitory activities against both targets. In particular, compound 11b was demonstrated to be most potent for MDM2 and HDAC, reaching the enzyme inhibition of 68% and 79%, respectively. Compound 11b also showed efficient antiproliferative activity towards MCF-7 cells with better potency than the reference drug SAHA and Nutlin-3. Furthermore, western blot analysis revealed that compound 11b increased the expression of p53 and Ac-H4 in MCF-7 cells in a dose-dependent manner. Our results indicate that dual inhibition of HDAC and MDM2 may provide a novel and efficient strategy for the discovery of antitumor drug in the future.

Mesothelium-Derived Factors Shape GATA6-Positive Large Cavity Macrophages.

The local microenvironment shapes macrophage differentiation in each tissue. We hypothesized that in the peritoneum, local factors in addition to retinoic acid can support GATA6-driven differentiation and function of peritoneal large cavity macrophages (LCMs). We found that soluble proteins produced by mesothelial cells lining the peritoneal cavity maintained GATA6 expression in cultured LCMs. Analysis of global gene expression of isolated mesothelial cells highlighted mesothelin (Msln) and its binding partner mucin 16 (Muc16) as candidate secreted ligands that potentially regulate GATA6 expression in peritoneal LCMs. Mice deficient for either of these molecules showed diminished GATA6 expression in peritoneal and pleural LCMs that was most prominent in aged mice. The more robust phenotype in older mice suggested that monocyte-derived macrophages were the target of Msln and Muc16. Cell transfer and bone marrow chimera experiments supported this hypothesis. We found that lethally irradiated Msln-/- and Muc16-/- mice reconstituted with wild-type bone marrow had lower levels of GATA6 expression in peritoneal and pleural LCMs. Similarly, during the resolution of zymosan-induced inflammation, repopulated peritoneal LCMs lacking expression of Msln or Muc16 expressed diminished GATA6. These data support a role for mesothelial cell-produced Msln and Muc16 in local macrophage differentiation within large cavity spaces such as the peritoneum. The effect appears to be most prominent on monocyte-derived macrophages that enter into this location as the host ages and also in response to infection.