Mut-p53 competes with SUMO-specific protease 1 (SENP1) to combine Rac1, a small GTPase, and sustains its SUMOylation to promote tumor progression in two breast cancer cell lines [SK-BR-3 (R175H) and MDA-MB468 (R273H)] (72). The gene discussed is TP53; the disease is neoplasm.