First, peptide generation and modification can be inhibited by low molecular mass protein 2 (LMP2), LMP7, and LMP10 in tumor cells.14–16 In liver cancer17 and gastric cancer,18 miR-23a and miR-502-5p, respectively, can inhibit the expression of LMP7 by interfering with interferon regulatory factor-1 (IRF-1), which is an essential factor in the INF-γ-mediated increase in LMP7;19 miR-451 has also been found to be able to directly regulate LMP7 in diabetic nephropathy,20 but whether such a regulatory relationship exists in tumors remains to be studied. Here, PSMB9 is linked to gastric cancer.