LACTB directly binds to the C-terminus of p53 to inhibit p53 degradation by preventing E3 ubiquitin-protein ligase Mdm2 from interacting with p53;The antitumorigenic effects of LACTB overexpression is counterbalanced by p53 ablation in colorectal cancer;The downregulated expression of LACTB is due to promoter methylation and histone deacetylation. The gene discussed is MDM2; the disease is colorectal cancer.