Potential role of CMPK1, SLC29A1, and TLE4 polymorphisms in gemcitabine-based chemotherapy in HER2-negative metastatic breast cancer patients: pharmacogenetic study results from the prospective randomized phase II study of eribulin plus gemcitabine versus paclitaxel plus gemcitabine (KCSG-BR-13-11).

BACKGROUND: In this study, we evaluated the association between genetic polymorphisms of 23 genes associated with gemcitabine metabolism and the clinical efficacy of gemcitabine in breast cancer patients. PATIENTS AND METHODS: This prospective, pharmacogenetic study was conducted in cooperation with a phase II clinical trial. A total of 103 genetic polymorphisms of the 23 genes involved in gemcitabine transport and metabolism were selected for genotyping. The associations of genetic polymorphisms with overall survival, progression-free survival (PFS), and 6-month PFS were analyzed. RESULTS: A total of 91 breast cancer patients were enrolled in this study. In terms of 6-month PFS, rs1044457 in CMPK1 was the most significant genetic polymorphism [55.9% for CT and TT and 78.9% for CC, P < 0.001, hazard ratio (HR): 4.444, 95% confidence interval (CI): 1.905-10.363]. For the rs693955 in SLC29A1, the median duration of PFS was 5.4 months for AA and 10.5 months for CA and CC (P = 0.002, HR: 3.704, 95% CI: 1.615-8.497). For the rs2807312 in TLE4, the median duration of PFS was 5.7 months for TT and 10.4 months for CT and CC (P = 0.005, HR: 4.948, 95% CI: 1.612-15.190). In survival analysis with a multi-gene model, the TT genotype of rs2807312 had the worst PFS regardless of other genetic polymorphisms, whereas the CA genotype of rs693955 or the CT genotype of rs2807312 without the AA genotype of rs693955 had the best PFS compared with those of other genetic groups (P < 0.001). CONCLUSIONS: Genetic polymorphisms of rs1044457 in CMPK1, rs693955 in SLC29A1, and rs2807312 in TLE4 were significantly associated with the 6-month PFS rate and/or the duration of PFS. Further studies with a larger sample size and expression study would be helpful to validate the association of genetic polymorphisms and clinical efficacy of gemcitabine.

A graphene mesh as a hybrid electrode for foldable devices.

A graphene mesh with arrays of micro-holes was fabricated on a polymer substrate using photolithography for use as an electrode in flexible devices. The optimal mesh structure with high optical transmittance and electrical conductivity was designed using a finite element method, in which the conductivity of the mesh was simulated as a function of structure, size, and periodicity of the hole array. The sheet resistance of the graphene mesh was lowered to that of a graphene monolayer by chemical doping and found to be 330 Ω Sq-1 at 98.5% transparency. The figure of merit of the doped graphene mesh was calculated to be 106 at 98% transmittance, a value that has not yet been reported for any conventional transparent electrode material. Due to strong bonding between the polymer and substrate, the hybrid electrode composed of a silver nanowire (AgNW)/graphene mesh coated with an over-coating layer exhibited more stable electrical characteristics during mechanical fatigue deformation compared to a hybrid film composed of a AgNW/graphene sheet. The AgNW/graphene sheet underwent breakdown at less than 20 000 cycles in cyclic bending tests with 6.5% strain, but the AgNW/graphene mesh showed a 38% increase in resistance at 20 000 cycles and no breakdown even at 100 000 cycles. Therefore, in this study, we propose a hybrid structure composed of a AgNW/graphene mesh, which is optically and mechanically superior to AgNW/graphene sheets, and therefore suitable for application as a transparent electrode in foldable devices with long-term stability.

Role of PIN1 on in vivo periodontal tissue and in vitro cells.

BACKGROUND: Although expression of peptidyl-prolyl cis/trans isomerase NIMA-interacting 1 (PIN1) was reported in bone tissue, the precise role of PIN1 in periodontal tissue and cells remain unclear. MATERIAL & METHODS: To elucidate the roles of PIN1 in periodontal tissue, its expression in periodontal tissue and cells, and effects on in vitro 4 osteoblast differentiation and the underlying signaling mechanisms were evaluated. RESULTS: PIN1 was expressed in mouse periodontal tissues including periodontal ligament cells (PDLCs), cementoblasts and osteoblasts at the developing root formation stage (postnatal, PN14) and functional stage of tooth (PN28). Treatment of PIN1 inhibitor juglone, and gene silencing by RNA interference promoted osteoblast differentiation in PDLCs and cementoblasts, whereas the overexpression of PIN1 inhibited. Moreover, osteogenic medium-induced activation of AMPK, mTOR, Akt, ERK, p38 and NF-jB pathways were enhanced by PIN1 siRNA, but attenuated by PIN1 overexpression. Runx2 expressions were induced by PIN1 siRNA, but downregulated by PIN1 overexpression. CONCLUSION: In summary, this study is the first to demonstrate that PIN1 is expressed in developing periodontal tissue, and in vitro PDLCs and cementoblasts. PIN1 inhibition stimulates osteoblast differentiation, and thus may play an important role in periodontal regeneration.

Five-year decreased incidence of surgical site infections following gastrectomy and prosthetic joint replacement surgery through active surveillance by the Korean Nosocomial Infection Surveillance System.

BACKGROUND: Surveillance of healthcare-associated infection has been associated with a reduction in surgical site infection (SSI). AIM: To evaluate the Korean Nosocomial Infection Surveillance System (KONIS) in order to assess its effects on SSI since it was introduced. METHODS: SSI data after gastrectomy, total hip arthroplasty (THA), and total knee arthroplasty (TKA) between 2008 and 2012 were analysed. The pooled incidence of SSI was calculated for each year; the same analyses were also conducted from hospitals that had participated in KONIS for at least three consecutive years. Standardized SSI rates for each year were calculated by adjusting for SSI risk factors. SSI trends were analysed using the Cochran-Armitage test. FINDINGS: The SSI rate following gastrectomy was 3.12% (522/16,918). There was a significant trend of decreased crude SSI rates over five years. This trend was also evident in analysis of hospitals that had participated for more than three years. The SSI rate for THA was 2.05% (157/7656), which decreased significantly from 2008 to 2012. The risk factors for SSI after THA included the National Nosocomial Infections Surveillance risk index, trauma, reoperation, and age (60-69 years). The SSI rate for TKA was 1.90% (152/7648), which also decreased significantly during a period of five years. However, the risk-adjusted analysis of SSI did not show a significant decrease for all surgical procedures. CONCLUSION: The SSI incidence of gastrectomy and prosthetic joint replacement declined over five years as a result of active surveillance by KONIS.

Trends in the distribution and antimicrobial susceptibility of causative pathogens of device-associated infection in Korean intensive care units from 2006 to 2013: results from the Korean Nosocomial Infections Surveillance System (KONIS).

BACKGROUND: For all countries, information on pathogens causing healthcare-associated infections is important in order to develop proper strategies for preventing and treating nosocomial infections. AIM: To assess the change in frequencies and antimicrobial resistance of pathogens causing device-associated infections (DAIs) in intensive care units (ICUs) in South Korea between July 2006 and June 2014. METHODS: Data from the Korean Nosocomial Infections Surveillance System (KONIS) were analysed, including three major DAI types in ICUs. FINDINGS: The frequency of Gram-negative bacteria gradually increased for central line-associated bloodstream infection (CLABSI) and ventilator-associated pneumonia (VAP) (from 24.6% to 32.6% and from 52.8% to 73.5%, respectively). By contrast, the frequency of Gram-positive bacteria decreased from 58.6% to 49.2% for CLABSI, and from 44.3% to 23.8% for VAP (P < 0.001). Staphylococcus aureus was the most frequent causative pathogen in CLABSI throughout the surveillance period, but for VAP was replaced as the most frequent pathogen by Acinetobacter baumannii as of 2010. Candida albicans was the most frequent pathogen for catheter-associated urinary tract infection. The meticillin resistance rate in S. aureus decreased from 95% to 90.2% (P < 0.001); amikacin resistance in Klebsiella pneumoniae and Escherichia coli decreased from 43.8% to 14.7% and from 15.0% to 1.8%, respectively (P < 0.001); imipenem resistance in A. baumannii increased from 52.9% to 89.8% (P < 0.001). CONCLUSION: The proportion of Gram-negative bacteria as nosocomial pathogens for CLABSI and VAP has increased. The prevalence of A. baumannii causing DAIs in Korean ICUs has increased rapidly, as has the rate of carbapenem resistance in these bacteria.

Frequency of FMR1 premutation carriers and rate of expansion to full mutation in a retrospective diagnostic FMR1 Korean sample.

Detection of female premutation (PM) carriers of fragile X syndrome may be important in that a PM allele from the mother can expand to a full mutation (FM) when transmitted to the fetus. Although the PM carrier frequency might be different in varying populations, there is a little data on the Korean population. Furthermore, the risks of expansion to FM have not been studied in Korean PM carriers. In this retrospective study, we estimated the female PM carrier frequency and the risks of expansion to FM in Korean diagnostic samples collected for FMR1 gene testing. Of 10,241 pre-conceptional or pregnant women, 13 PM [1 in 788; 95% confidence interval (CI), 1/1,250-1/455] and 75 intermediate allele carriers (1 in 137; 95% CI, 1/172-1/110) were identified. In 26 prenatal diagnoses cases, the PM allele was transmitted to the fetus in 13 pregnancies (50%), and five of these expanded to FM. All of the maternal alleles exceeding 70 repeats expanded to FM. In conclusion, the PM frequency in Korean diagnostic samples was lower than that reported in Western populations, while the risk for FM expansion in alleles exceeding 70 repeats might be higher than expected based upon previous reports.

Loss of PTEN induces microtentacles through PI3K-independent activation of cofilin.

Loss of PTEN tumor suppressor enhances metastatic risk in breast cancer, although the underlying mechanisms are poorly defined. We report that homozygous deletion of PTEN in mammary epithelial cells induces tubulin-based microtentacles (McTNs) that facilitate cell reattachment and homotypic aggregation. Treatment with contractility-modulating drugs showed that McTNs in PTEN(-/-) cells are suppressible by controlling the actin cytoskeleton. Because outward microtubule extension is counteracted by actin cortical contraction, increased activity of actin-severing proteins could release constraints on McTN formation in PTEN(-/-) cells. One such actin-severing protein, cofilin, is activated in detached PTEN(-/-) cells that could weaken the actin cortex to promote McTNs. Expression of wild-type cofilin, an activated mutant (S3A), and an inactive mutant (S3E) demonstrated that altering cofilin phosphorylation directly affects McTNs formation. Chemical inhibition of PI3K did not reduce McTNs or inactivate cofilin in PTEN(-/-) cells. Additionally, knock-in expression of the two most common PI3K-activating mutations observed in human cancer patients did not increase McTNs or activate cofilin. PTEN loss and PI3K activation also caused differential activation of the cofilin regulators, LIM-kinase1 (LIMK) and Slingshot-1L (SSH). Furthermore, McTNs were suppressed and cofilin was inactivated by restoration of PTEN in the PTEN(-/-) cells, indicating that both the elevation of McTNs and the activation of cofilin are specific results arising from PTEN loss. These data identify a novel mechanism by which PTEN loss could remodel the cortical actin network to facilitate McTNs that promote tumor cell reattachment and aggregation. Using isogenic MCF-10A PTEN(-/-) and PIK3CA mutants, we have further demonstrated that there are clear differences in activation of cofilin, LIMK and SSH between PTEN loss and PI3K activation, providing a new evidence that these mutations yield distinct cytoskeletal phenotypes, which could have an impact on tumor biology.

Factors leading to under-reporting of tuberculosis in the private sector in Korea.

OBJECTIVE: To identify factors associated with under-reporting of tuberculosis (TB) in the private sector in Korea. DESIGN: A cross-sectional study of 37,820 cases in whom treatment was initiated between January and December 2008 using data from the Nationwide Medical Records Survey of Patients with TB. Adjusted odds ratios (aOR) for under-reporting with respect to socio-demographic and clinical factors were estimated. RESULTS: Among the 37,820 identified cases, 21,611 (57.1%) were reported to the Korean TB Surveillance System. Factors associated with under-reporting on univariate analysis included young children, foreign-born persons, non-multidrug-resistant TB, persons prescribed fewer than four anti-tuberculosis drugs, non-performance of or negative result on sputum smear and extra-pulmonary TB (particularly abdominal or genitourinary TB). For pulmonary TB, cases with no sputum smear results vs. smear-positive patients (aOR 2.23, P < 0.001) and those prescribed <4 drugs vs. those who were prescribed ≥4 drugs (aOR 1.60, P < 0.001) were strongly related to under-reporting on multivariate analysis. CONCLUSION: The extent of under-reporting was greater among young children, persons who had not received sputum smear testing and those who had been prescribed fewer than four drugs. Furthermore, TB diagnostic investigations were often inadequate. Education on reporting requirements, including the importance of following guidelines on TB management, and a stricter enforcement of the existing TB Prevention Law, are needed.

c-Src differentially regulates the functions of microtentacles and invadopodia.

During metastasis, invading cells produce various actin-based membrane protrusions that promote directional migration and proteolysis of extracellular matrix (ECM). Observations of actin staining within thin, tubulin-based microtentacle (McTN) protrusions in suspended MDA-MB-231 tumor cells, prompted an investigation of whether McTNs are structural or functional analogs of invadopodia. We show here that MDA-MB-231 cells are capable of producing invadopodia and McTNs, both of which contain F-actin. Invadopodium formation was enhanced by the expression of a constitutively active c-Src kinase, and repressed by the expression of dominant-negative, catalytically inactive form of c-Src. In contrast, expression of inactive c-Src significantly increased McTN formation. Direct inhibition of c-Src with the SU6656 inhibitor compound also significantly enhanced McTN formation, but suppressed invadopodia, including the appearance of F-actin cores and phospho-cortactin foci, as well as completely blocking focal degradation of ECM. In addition, silencing of Tks5 in Src-transformed fibroblasts blocked invadopodia without affecting McTNs. Genetic modification of c-Src activity that promoted McTN formation augmented capillary retention of circulating tumor cells in vivo and rapid re-attachment of suspended cells in vitro, even though invadopodia were strongly suppressed. These results indicate that McTNs are capable of enhancing tumor cell reattachment, even in the absence of Tks5 and active Src, and define separate cytoskeletal mechanisms and functions for McTNs and invadopodia.

Blood pressure changes after intravitreal bevacizumab in patients grouped by ocular pathology.

PURPOSE: We evaluated the effects of intravitreal injection of bevacizumab (Avastin; Novartis, Basel, Switzerland) on blood pressure (BP) in the context of ocular vascular pathology. METHODS: This study retrospectively examined 135 consecutive patients treated with intravitreal injections of 1.25 mg bevacizumab for retinal vascular disease; there were 61 cases of diabetic retinopathy, 30 of retinal vein occlusion, 35 of choroidal neo-vascularization (CNV), and 9 of other retinal vascular diseases. BP was measured before injection and at 30 min, 1 day, 1 week, 3 weeks, and thereafter monthly over a 6-month period. RESULTS: In the CNV group, 30-min post-injection systolic values were significantly higher than baseline, and systolic and diastolic values after 1 day, 1 week, and 3 weeks were significantly lower than before injection. No other pressure measurement differed significantly from baseline values in the other groups. DISCUSSION: Intravitreal bevacizumab injection is safe in terms of its effect on BP, regardless of ocular pathology.

Metastatic breast tumors express increased tau, which promotes microtentacle formation and the reattachment of detached breast tumor cells.

The cytoskeletal organization of detached and circulating tumor cells (CTCs) is currently not well defined and may provide potential targets for new therapies to limit metastatic tumor spread. In vivo, CTCs reattach in distant tissues by a mechanism that is tubulin-dependent and suppressed by polymerized actin. The cytoskeletal mechanisms that promote reattachment of CTCs match exactly with the mechanisms supporting tubulin microtentacles (McTN), which we have recently identified in detached breast tumor cells. In this study, we aimed to investigate how McTN formation is affected by the microtubule-associated protein, tau, which is expressed in a subset of chemotherapy-resistant breast cancers. We demonstrate that endogenous tau protein localizes to McTNs and is both necessary and sufficient to promote McTN extension in detached breast tumor cells. Tau-induced McTNs increase reattachment of suspended cells and retention of CTCs in lung capillaries. Analysis of patient-matched primary and metastatic tumors reveals that 52% possess tau expression in metastases and 26% display significantly increased tau expression over disease progression. Tau enrichment in metastatic tumors and the ability of tau to promote tumor cell reattachment through McTN formation support a model in which tau-induced microtubule stabilization provides a selective advantage during tumor metastasis.

A novel hemoglobin variant beta135(H13) Ala > Asp identified in an asymptomatic Korean family by direct sequencing: suggesting a new insight into Hb Beckman mutation.

This article describes the clinical observation of a novel hemoglobin (Hb) variant found during the course of routine blood testing on a 61-year-old subject. The Hb variant was observed during HbA1c testing by ion-exchange high-performance liquid chromatography. Alkaline electrophoresis and DNA sequencing confirmed the presence of a new Hb variant, HBB:c.407C > A (p.Ala136Asp). This mutation has been reported to induce Hb Beckman variant in the Globin Gene Server. However, it was different from the only experimental report for Hb Beckman by Rahbar, Lee & Asmeron (p.Ala136Glu; Hb Beckman alpha2 beta2 135(H13) ala-to-glu: a new unstable variant and reduced oxygen affinity. Blood 78, 204a). And our case was asymptomatic with normal lab findings, while Rahbar et al.'s case showed the clinical manifestations of chronic anemia. This would be a report for a novel Hb variant suggesting new insight of Hb Beckman variant. This would be a report of a novel Hb variant suggesting new insights into Hb Beckman variant.

Calibration and standardization of the emission light path of confocal microscopes.

Recently, there has been a large expansion in the usage of optical microscopes for obtaining quantitative information from biological samples in order to determine fundamental biological information such as molecular kinetics and interaction, and heterogeneity within cell populations. Consequently, we built a highly stable, uniform, isotropically emitting and convenient-to-use light source, and designed image analysis procedures for calibrating the emission light path of optical microscopes. We used the source and procedures to analyse the quantitative imaging properties of a widely used model of laser scanning confocal microscope. Results showed that the overall performance was as high as could be expected given the inherent limitations of the optical components and photomultiplier tubes. We observed that the photon detection efficiency did not vary with photomultiplier tube gain and that the highest dynamic range was achieved with relatively low gain and 12-bit digitization. Practical applications of the light source for checking the transmission of optical components in the emission light path are presented.

Effects of ADP on different inhibitory properties of brain glutamate dehydrogenase isoproteins by perphenazine.

Incubation of glutamate dehydrogenase isoproteins (GDH I and GDH II) from bovine brains with perphenazine resulted in a time-dependent loss of enzyme activity. 2-Oxoglutarate and NADH, separately or together, gave partial but not complete protection against the inhibition. Although there were no detectable differences between GDH I and GDH II in inhibition by perphenazine in the absence of ADP, the sensitivities to the inhibition by the drug were significantly distinct for the two isoproteins in the presence of ADP. Low concentrations of ADP (0.05-0.20 mM) did not interfere with the inhibition of GDH I and GDH II by perphenazine. However, in the presence of high concentrations of ADP (0.5-1.0 mM), inhibitory effects of perphenazine on GDH isoproteins were significantly diminished as determined by enzyme kinetics and quantitative affinity chromatography on perphenazine-Sepharose. GDH I was more sensitively reacted with ADP than GDH II on the inhibition by perphenazine. Since physiological ADP levels can vary from 0.05 to > 1.0 mM depending on the rate of oxidative phosphorylation, our results suggest a possibility that two types of GDHs are differently regulated by the antipsychotic actions of perphenazine depending on the physiological concentrations of ADP. GTP and L-leucine, other well-known allosteric regulators, did not affect the inhibitory actions of perphenazine on bovine brain GDH isoproteins.

An essential histidine residue in GTP binding domain of bovine brain glutamate dehydrogenase isoproteins.

Greater than 90% of the original activity of the enzymes remained after modification of histidine residues of glutamate dehydrogenase (GDH) isoproteins from bovine brains with diethyl pyrocarbonate (DEPC). This suggests that the DEPC modified histidine residues are not critically involved in the catalysis of the GDH isoproteins. The influence of DEPC modified histidine residue(s) on binding of GTP to GDH isoproteins was investigated by protection studies. These studies showed that inhibition of GDH isoproteins by GTP was protected by preincubation of GDH isoproteins with DEPC. The amount of protection was dependent on the concentration of DEPC. The GTP inhibition was fully protected by preincubation of GDH isoproteins with DEPC at saturating concentrations. These results indicate that the histidine residues may play an important role in the GTP binding on GDH isoproteins. Spectrophotometric studies showed that three histidine residues per enzyme subunit were able to react with DEPC in the absence of GTP, whereas two histidine residues per enzyme subunit interacted with DEPC when the enzymes were preincubated with GTP. These results indicate that one of the histidine residues is involved in the GTP binding domain of GDH isoproteins. The quantitative affinity chromatographic studies showed that the influence of GTP on the binding of GDH isoproteins to DEPC-Sepharose was significantly distinct for the two GDH isoproteins. GDH I was more sensitively affected by GTP than GDH II in the binding affinity for DEPC-Sepharose. ADP, another well-known allosteric regulator, showed no significant changes in the interaction of DEPC with GDH isoproteins.

A case of nodular scleritis in association with Behcet's disease.

Approximately 50% of patients with scleritis are known to be associated with systemic connective tissue diseases or vasculitic diseases such as rheumatoid arthritis (RA), Wegener's granulomatosis, relapsing polychondritis, and systemic lupus erythematosus. The patients with scleritis in association with Behcet's disease (BD) have been rarely described in the literature. We report a 46-year-old female patient with BD who developed the nodular scleritis.

SJ-3366, a unique and highly potent nonnucleoside reverse transcriptase inhibitor of human immunodeficiency virus type 1 (HIV-1) that also inhibits HIV-2.

We have identified and characterized a potent new nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1) that also is active against HIV-2 and which interferes with virus replication by two distinct mechanisms. 1-(3-Cyclopenten-1-yl)methyl-6-(3,5-dimethylbenzoyl)-5-ethyl-2,4-pyrimidinedione (SJ-3366) inhibits HIV-1 replication at concentrations of approximately 1 nM, with a therapeutic index of greater than 4 x 10(6). The efficacy and toxicity of SJ-3366 are consistent when evaluated with established or fresh human cells, and the compound is equipotent against all strains of HIV-1 evaluated, including syncytium-inducing, non-syncytium-inducing, monocyte/macrophage-tropic, and subtype virus strains. Distinct from other members of the pharmacologic class of NNRTIs, SJ-3366 inhibited laboratory and clinical strains of HIV-2 at a concentration of approximately 150 nM, yielding a therapeutic index of approximately 20,000. Like most NNRTIs, the compound was less active when challenged with HIV-1 strains possessing the Y181C, K103N, and Y188C amino acid changes in the RT and selected for a virus with a Y181C amino acid change in the RT after five tissue culture passages in the presence of the compound. In combination anti-HIV assays with nucleoside and nonnucleoside RT and protease inhibitors, additive interactions occurred with all compounds tested with the exception of dideoxyinosine, with which a synergistic interaction was found. Biochemically, SJ-3366 exhibited a K(i) value of 3.2 nM, with a mixed mechanism of inhibition against HIV-1 RT, but it did not inhibit HIV-2 RT. SJ-3366 also inhibited the entry of both HIV-1 and HIV-2 into target cells. On the basis of its therapeutic index and multiple mechanisms of anti-HIV action, SJ-3366 represents an exciting new compound for use in HIV-infected individuals.

Characterization of bacteriophage lambda excisionase mutants defective in DNA binding.

The bacteriophage lambda excisionase (Xis) is a sequence-specific DNA binding protein required for excisive recombination. Xis binds cooperatively to two DNA sites arranged as direct repeats on the phage DNA. Efficient excision is achieved through a cooperative interaction between Xis and the host-encoded factor for inversion stimulation as well as a cooperative interaction between Xis and integrase. The secondary structure of the Xis protein was predicted to contain a typical amphipathic helix that spans residues 18 to 28. Several mutants, defective in promoting excision in vivo, were isolated with mutations at positions encoding polar amino acids in the putative helix (T. E. Numrych, R. I. Gumport, and J. F. Gardner, EMBO J. 11:3797-3806, 1992). We substituted alanines for the polar amino acids in this region. Mutant proteins with substitutions for polar amino acids in the amino-terminal region of the putative helix exhibited decreased excision in vivo and were defective in DNA binding. In addition, an alanine substitution at glutamic acid 40 also resulted in altered DNA binding. This indicates that the hydrophilic face of the alpha-helix and the region containing glutamic acid 40 may form the DNA binding surfaces of the Xis protein.