Given a passage with a context and an answer, construct a question on the basis of the information present in the passage. Construct the question in such a way that (i) it is unambiguous, (ii) it is answerable from the passage, (iii) its answer is unique (iv) it answer uses text phrases from the passage. Avoid creating questions that (i) can't be answered correctly without actually understanding the passage and (ii) uses the same words or phrases given in the passage.

Ex Input:
Context: The B cell chemoattractant chemokine ligand 13 (CXCL13) is emerging as a new biochemical marker in RA. This study was undertaken to dissect the relationship between CXCL13 expression levels in the synovium and clinico-pathological variables relevant to RA pathogenesis and outcome.', 'Synovial tissues from 71 RA patients were evaluated by immunohistochemistry. Thirty paired samples were used for comparative gene expression analysis by quantitative real-time PCR. CXCL13 levels were analysed in relation to cellular, molecular and clinical features of inflammation, lymphocyte activation and joint damage.', 'In patients with early disease (<12 months duration), CXCL13 expression correlated significantly with synovial markers of local disease activity and systemic inflammation. Such correlation was less evident in established RA. Notably, the association with lymphocyte infiltration and with expression of B/T cell-related activation and proliferation genes, such as activation-induced cytidine deaminase, IFN-γ and IL-2, remained highly significant independent of disease duration and local disease activity. Patients featuring the highest levels of CXCL13 were more frequently ACPA positive and IgG ACPA titres were increased in the high CXCL13 expression group. Furthermore, the frequency of erosive disease on radiographs was significantly higher in the upper tertile of CXCL13 expression (P = 0.01 with adjustment for disease duration and ACPA). Accordingly, synovial CXCL13 and the local receptor activator of nuclear factor κB ligand (RANKL)/osteoprotegerin (OPG) ratio significantly co-varied (ρ = 0.52, P < 0.01), independent of the level of local inflammation.
Answer: Synovial CXCL13 appears to be a marker of a more severe pattern of RA disease, characterized by increased lymphocyte activation and bone remodelling beyond the level of conventional markers of inflammation.

Ex Output:
Are high expression levels of the B cell chemoattractant CXCL13 in rheumatoid synovium a marker of severe disease?


Ex Input:
Context: To investigate the expression and clinical significance of programmed cell death 4 (PDCD4), a novel metabolism-associated gene, during polycystic ovary syndrome (PCOS) pathogenesis.', 'Case-control study.', 'University hospital.', 'A total of 77 PCOS patients and 67 healthy women as matched controls.', 'PDCD4 expression in peripheral blood mononuclear cells analyzed by quantitative real-time polymerase chain reaction, and apoptosis of granulosa cells (GCs) detected by flow cytometry, terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), and small-interfering RNA.', 'PDCD4 expression, body mass index (BMI), insulin 0, insulin 120, glucose 120, homeostasis model assessment for insulin resistance (HOMA-IR), homeostasis model assessment for β-cell function (HOMA-β), triglycerides, high-density lipoprotein (HDL), and GC apoptosis.', 'The PCOS patients had higher PDCD4 expression, but BMI was similar as matched with the obese group, which positively correlated with BMI, insulin 0, insulin 120, glucose 120, HOMA-IR, HOMA-β, triglycerides and negatively correlated with HDL (P<.05). After metformin treatment, PDCD4 expression was distinctly down-regulated for the obese women with PCOS with insulin resistance. Compared with the healthy controls, the apoptosis percentage of GCs was higher in the PCOS group and was decreased by knocking down PDCD4. Furthermore, expression of proapotosis factor Bax and the Bax/Bcl-2 ratio were lower, whereas the expression of antiapoptosis factor Bcl-2 was increased. In a multivariate logistic regression analysis, the level of PDCD4 expression independently related to the odds of PCOS risk after controlling for estradiol and insulin 120 (odds ratio 1.318).
Answer: Our study suggests for the first time that higher PDCD4 expression might play an important role in PCOS pathogenesis by affecting obesity, insulin resistance, lipid metabolism disorders, and GC apoptosis.

Ex Output:
Is higher PDCD4 expression associated with obesity , insulin resistance , lipid metabolism disorders , and granulosa cell apoptosis in polycystic ovary syndrome?


Ex Input:
Context: To explore the role of SCF/c-Kit signaling in the invasion of bladder cancer T24 cells.', 'Western blotting was used to detect the expression of c-Kit and PI3K pathway activation stimulated by stem cell factor (SCF) in T24 cells. The invasiveness of T24 cells before and after SCF stimulation and Wortmannin (aspecific PI3K inhibitor) treatment was evaluated using Transwell invasion assay (direct and indirect counting methods).', 'T24 cells expressed c-Kit protein and showed obvious Akt phosphorylation after stimulation with SCF (1 ng/ml) for 24 h. Compared to the control group, SCF stimulation (1 ng/ml) caused a greater number of T24 cells to migrate through the polycarbonate film (P<0.01), and this effect was blocked by the application of Wortmannin before the stimulation.
Answer: SCF/c-Kit signaling promotes the invasiveness of T24 cells, and this effect is mediated by the PI3K pathway.

Ex Output:

Does [ SCF/c-Kit signaling promote invasion of T24 cells via PI3K pathway ]?