To further confirm the roles of BIRC2 in BRD7-mediated cell proliferation, cell cycle progression and apoptosis, we detected the expression of cell cycle and apoptosis-related molecules by western blotting, and the results showed that BRD7 decreased the abundances of cell cycle markers such as CDK4 and cyclinD1, cell apoptosis marker such as Bcl2, and increased the protein level of P21 as well as the apoptosis marker cleaved PARP in both 5-8 F and HNE1 cells, while overexpression of BIRC2 produced the exact opposite results, indicating the oncogenic function of BIRC2 in NPC. This evidence concerns the gene CDK4 and nasopharyngeal carcinoma.