TP53 and skin neoplasm: UV exposure is the main environmental cause of skin cancer.43, 44 UV causes DNA damage, inducing activation of ataxia telangiectasia-related kinase and/or ataxia telangiectasia mutated kinase; then p53 is activated through phosphorylation of ser-15 and ser-37.45 Activated p53 then upregulates the expression of Bax.