PSMB9 and cancer: In this study, we revealed for the first time that the ectopic expression of miR-19a or miR-19b-1 in cancer cells significantly downregulated the expression of PSMB8, PSMB9 and IFN-regulated genes (i.e., IRF7, IFI6, IFIT1, IFITM1, IFI27 and IFI44L), which have never been reported in other physiological and pathological processes.