TP53 and neoplasm: The above results show that LACTBM5L+R469K not only reduces the protein level of wt‐p53 via enhancing PSMB7 catalytic activity in OS, but also protects p53R156P protein from lysosomal degradation in tumors harbouring p53R156P mutation, which suggests that LACTBM5L+R469K could be a dual‐regulator for regulating p53 protein in tumor and inhibiting LACTBM5L+R469K is an attractive strategy for the treatment of OS, which can take advantage to patient harbouring wt‐p53 or p53R156P mutation.