Moreover, we further found that apoptosis-related proteins consisting of Bcl-2, Bcl-w, clAP-2, HSP27, IGF-II, Survivin, sTNF-R1, sTNF-R2, TNF-α, and XIAP, were significantly downregulated in HCC cells with PSMC2 knockdown, which contributed to the regulation of PSMC2 in cell proliferation and apoptosis,. Here, XIAP is linked to hepatocellular carcinoma.