PIK3C3 and esophageal squamous cell carcinoma: Methods: We systematically evaluated association between seven candidate seven SNPs (CXCR4 rs6430612, TERT rs13172201, TERT rs10069690, TERT rs2853676, TERT rs451360, OBFC1 rs4387287, and VPS34 rs2162440) and ESCC risk in two case-control sets consisting of 1588 ESCC cases and 1600 controls.