RB1 and gastric cancer: Analysis of TCGA data revealed that 66% of the GC patients exhibited altered expression of at least one of the following cell cycle related genes: RB1, CCND1, CCNE1, CDK2, CDK4, CDK6, CDKN2A, CDKN2B, E2F1, E2F2, E2F3, and E2F454.