It is a 44 kDa1 nuclearprotein encoded by the TP53 gene located on the shortarm of chromosome 17.2,3 The wild-type p53 protein (p53-WT)plays key roles in many important biological processes by regulatingthe transcription of several target genes,4 thereby controlling cell proliferation, aging and DNA repair processes,as well as cell death in oncogenic cells.5 As a tumor suppressor, the p53 protein checks the correctness ofthe DNA sequence in cells during the cell cycle phase and, in caseof damage, induces mechanisms leading to its repair. The gene discussed is TP53; the disease is neoplasm.