Furthermore, the biological function experiments of GC cells in vitro showed that the proliferation of MKN-45 cells was inhibited after knockdown POLR2A, the overall cell cycle was suppressed, the expression of cyclins and CDKs was down-regulated, apoptosis increased, and the expression of anti-apoptotic proteins PARP and BCL2 is down-regulated, and the overexpression of POLR2A in SGC-7901 cells has the opposite effect of knockdown POLR2A in MKN-45 cells, these results indicated that POLR2A promoted the proliferation of GC by advancing the cell cycle and inhibiting apoptosis. This evidence concerns the gene BCL2 and gastric cancer.