We found that the normal immortal human gastric mucosal epithelial cell line GES-1 expressed high level of p16(INK4a); while 3 of 8 gastric cancer cell lines expressed lower level of p16(INK4a), and 5 of 8 gastric cancer cell lines did not express detectable p16(INK4a). This evidence concerns the gene CDKN2A and gastric cancer.