reported that PSMB7 upregulation in multiple myeloma is related to bortezomib resistance and poor prognosis.[26] And other studies showed that high PSMB7 expression indicated poor prognosis in patients with colon cancer and breast cancer.[27, 28] Our study first reports that M5L and R469K mutations are crucial for the binding of LACTB to PSMB7, and PSMB7 mediates the regulation of LACTBM5L+R469K to wt‐p53 protein, and targeting PSMB7 could be valuable strategy for regulating wt‐p53 to treat tumor. The gene discussed is LACTB; the disease is breast cancer.