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.

[Q]: Context: Lung cancer is the most important cause of cancer mortality worldwide, but the underlying mechanisms of this disease are not fully understood. Copy number variations (CNVs) are promising genetic variations to study because of their potential effects on cancer.', 'Here we conducted a pilot study in which we systematically analyzed the association of CNVs in two lung cancer datasets: the Environment And Genetics in Lung cancer Etiology (EAGLE) and the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial datasets. We used a preestablished association method to test the datasets separately and conducted a combined analysis to test the association accordance between the two datasets. Finally, we identified 167 risk SNP loci and 22 CNVs associated with lung cancer and linked them with recombination hotspots. Functional annotation and biological relevance analyses implied that some of our predicted risk loci were supported by other studies and might be potential candidate loci for lung cancer studies.\Question: Does combined analysis with copy number variation identify risk loci in lung cancer?
[A]: Our results further emphasized the importance of copy number variations in cancer and might be a valuable complement to current genome-wide association studies on cancer.


[Q]: Context: Stat6 signaling is active in cancer cells and IL-4-induced Stat6 activities or Stat6 activational phenotypes vary among cancer cells. This study aimed at investigating possible mechanism(s) involved in the formation of varying Stat6 activities/phenotypes.', "Stat6 regulatory genes, SOCS-1 and SHP-1, were examined for mRNA expression using RT-PCR, and their promoter DNA methylation was assayed by methylation-specific PCR in Stat6-phenotyped colon cancer cell lines. DNA methylation was then verified by sequencing. RT-PCR assay and Western blotting were used to detect the expression of SOCS-1 and SHP-1 after demethylation using 5-aza-2'-deoxycytidine.", "Compared with Stat6(null) Caco-2 cells, Stat6(high) HT-29 cells showed decreased constitutive expression of SOCS-1 and SHP-1, which correlated with DNA hypermethylation in these genes' promoters. Interestingly, demethylation in HT-29 cells recovered the constitutive expression of SOCS-1 and SHP-1.\Question: Does dNA methylation regulate constitutive expression of Stat6 regulatory genes SOCS-1 and SHP-1 in colon cancer cells?
[A]: These findings suggest that DNA methylation controls the constitutive expression of negative Stat6 regulatory genes, which may affect Stat6 activities.


[Q]: Context: Cerebrovascular accidents (CVAs) frequently coexist with coronary artery disease (CAD) and adversely affect prognosis in patients with CAD; however, fewer studies have investigated the role of prior ischemic stroke on the outcomes of percutaneous coronary intervention (PCI). The aim of this study was to determine the safety and effectiveness of PCI in patients with a prior ischemic stroke.', 'A review of patients who underwent PCI between June 2003 and September 2005 (n=3893) at the Beijing Anzhen Hospital of Capital University of Medical Science, identified 295 PCI patients with a prior ischemic stroke (≥ 3 months) and 3598 patients without a prior stroke. To investigate whether prior history of an ischemic stroke was independently associated with increased risk of adverse PCI outcomes, prognostic parameters were analyzed using univariate analysis and Cox multivariate regression analysis. Propensity score analysis was then used to match the two subgroups of patients based on multiple factors known to impact cardiac outcome.', 'Patients with a prior ischemic stroke had more frequent high-risk baseline characteristics (diabetes, hypertension, hyperlipidemia and prior myocardial infarction). No significant differences were found in the major adverse cardiac and cerebrovascular event (MACCEs) rates between the two groups (1.7% in the stroke group vs. 1.4% in the non-stroke group; p=0.06). Diabetes mellitus, triple vessel CAD, number of diseased vessels, chronic total occlusion and previous myocardial infarction were independent predictors of MACCE in patients with prior stroke undergoing PCI.\Question: Is prior ischemic stroke associated with worse clinical outcomes in patients undergoing percutaneous coronary intervention?
[A]:
This study demonstrates that, in daily clinical practice, PCI can be provided safely and with good results to patients with a prior ischemic stroke (≥ 3 months).