TCF7L2 and esophageal squamous cell carcinoma: The TCF7L2 rs7903146 C>T, rs290481 T>C, LEP rs7799039 A>G, rs2167270 G>A and LEPR rs1137100 G>A, rs1137101 G>A and rs6588147 G>A polymorphisms were genotyped by SNPscan genotyping assays in 507 ESCC cases and 1,496 non-cancer controls.