According to the results of Human Apoptosis Antibody Array, PSMC2 knockdown increased the levels of apoptosis-related proteins Bax, BIM, CD40, CD40L, cytoC, IGFBP-3, IGFBP-5, p21, p27, and p53 in gastric cancer cells, revealing that PSMC2 might induce cell apoptosis by regulating these apoptosis-related proteins. The gene discussed is CD40; the disease is gastric cancer.