In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Example Input: Context: The caudal-type homeodomain transcriptional factor CDX2, a member of the caudal-related homeobox gene family, plays a crucial role in the regulation of cell proliferation and differentiation in the gut. Recent studies have reported that expression of CDX2 was an independent marker of outcome in patients with resected adenocarcinoma of ampulla of Vater, gastric cancer, and colon cancer. The clinicopathological significance of CDX2 expression has hitherto remained unclear in biliary tract carcinoma (BTC). The aim of this study was to determine whether CDX2 expression in BTC indicates clinical outcome.', 'The expression of CDX2 was investigated immunohistochemically in surgically resected specimens from 164 patients with BTC, including 74 intrahepatic cholangiocarcinomas, 49 extrahepatic cholangiocarcinomas, and 41 gallbladder carcinomas. The correlation between expression of CDX2 and clinicopathological factors, including overall survival, tumor location, tumor stage, and degree of tumor differentiation, was examined in patients with BTC.', 'In total, 27 of the 164 (16.46%) patients with BTC expressed CDX2. The frequency of CDX2 expression was much higher in the extrahepatic cholangiocarcinomas (22.45%) and gallbladder carcinomas (29.27%) than in the intrahepatic cholangiocarcinomas (5.41%), the difference being statistically significant (P = 0.002). Factors influencing survival on univariate analysis were tumor stage (P < 0.00001), degree of tumor differentiation (P = 0.0002), and CDX2 expression (P = 0.01). On multivariate analysis using the Cox proportional hazard model, CDX2 expression and tumor stage were independent prognostic factors in patients with BTC.\Question: Is expression of the caudal-type homeodomain transcription factor CDX2 related to clinical outcome in biliary tract carcinoma?
Example Output: Expression of CDX2 was an independent indicator of outcome in patients with BTC in addition to tumor stage and tumor differentiation. The mechanism by which CDX2 expression influences behavior of biliary tract carcinoma needs further investigation.

Example Input: Context: To determine whether fertilization rate serves as a biological assay, reflects oocyte quality, and may be used to help predict patient implantation rate.', 'Retrospective cohort study.', 'Academic center.', 'Couples undergoing 3603 in vitro fertilization (IVF) cycles from 2001 to 2007.', 'None.', 'We compared the implantation rate among cycles with high versus low fertilization rate. Univariate analyses were performed to determine the association of implantation rate with potential confounding variables: age, day-3 follicle-stimulating hormone level, day-3 estradiol level, antral follicle count, oocyte number, cycle attempts, embryo grading, and number of embryos transferred. Multivariate analysis was then performed to determine whether the fertilization rate remained an independent predictor.', 'Cutoffs for fertilization rate were 50% for intracytoplasmic sperm injection (ICSI) and 75% for conventional insemination. Higher ICSI fertilization was statistically significantly associated with the implantation rate (25.2% vs. 17.8 %). After adjusting for variables associated with implantation rate, fertilization rate for ICSI remained a strong independent predictor of implantation. Higher conventional insemination fertilization was statistically significantly associated with implantation (32.1% vs. 25.7%) and remained a statistically significant predictor after adjustment.\Question: Is fertilization rate an independent predictor of implantation rate?
Example Output: Fertilization is a strong, independent predictor of implantation rate and may be useful in modeling to guide decision making for the number of embryos to transfer.

Example Input: Context: We evaluated assays for the measurement of acute phase protein levels in plasma for their usefulness to identify sensitively an inflammatory response to active cytomegalovirus CMV infection in HIV-infected patients.', 'Plasma samples were collected from 28 CMV-seropositive patients with advanced HIV-infection (CD4-cell count <200/microl) before commencement of antiretroviral therapy. Sensitivity, specificity, and area under receiver operating characteristic curve for the selected acute phase protein assays (haptoglobin, fibronectin, high-sensitivity C-reactive protein (hs-CRP), human interleukin-6, serum amyloid A (SAA), and human lipopolysacharide binding protein) were compared with results of a CMV-specific PCR assay.', "CMV viremia was detectable in 8/28 patients. Levels of SAA correlated well with those of hs-CRP (r' = 0.439, P = 0.019 (Spearman rank correlation)). Levels of SAA >3 mg/L discriminated with 100% sensitivity and 40% specificity between HIV-infected patients with and without active CMV infection. Sensitivity of fibronectin was 100% and specificity 15% at a threshold-value corresponding with the lower limit of normal values as defined by the manufacturer of the assay (>29 mg/dL). Levels of the other acute phase proteins evaluated did not correlate with detection of CMV-DNA in plasma.\Question: Is aymptomatic CMV viremia associated with increased levels of serum amyloid A in patients with advanced HIV-infection?
Example Output:
Increased levels of SAA indicate sensitively an inflammatory response to active CMV infection. Use of a CMV-specific virological assay is required to confirm the specificity of a high SAA-level but may be limited to samples with high SAA-levels. Hence, screening for increased levels of SAA in patients with advanced HIV-infection may allow early identification of active CMV infection.