PSMB8 and gastric cancer: As shown in Supplementary Figure 2A and 2B, PSMB8 and PBK in microarray datasets (Cho et al. [18], and D'Errico et al. [19]) were overexpressed in gastric cancer tissues compared with that in normal tissues (P = 0.006, P = 0.007, P = 0.001, P = 4.34E-9).