For OS, 12 prognostic PSM genes (i.e. PSMA1, PSMA4, PSMB4-5, PSMB8, PSMB10, PSMD2, PSMD11-12, PSMD14, PSME2, and PSMG1; PSM class I/II/III/V) were identified in ≥ 30% of cancer types (Fig. 6C), whereas only two PSM genes (PSMA1, PSMD11; PSM class I/II) were identified for PFI (Fig. 6D). This evidence concerns the gene PSMB4 and cancer.