To confirm our prior results that metformin and everolimus treatment induced cancer cell death by apoptosis and cell-cycle arrest, we determined the expressions of apoptosis-, replication-, and cell-cycle-related proteins, including PARP-1, Bcl-2, Bax, caspase-3, PCNA, P27, and P21, by Western blotting. This evidence concerns the gene CDKN1A and cancer.