We first performed quantitative RT-PCR to measure the expression levels of HNF4A-P1 and HNF4A-P2 in diverse gastric cancer cell lines and selected two cell lines (KATO-III and MNK1), which expressed HNF4A-P1 and HNF4A-P2 at low levels (Supplementary Figure S5B and S5C). This evidence concerns the gene HNF4A and gastric cancer.