Numerous previous studies have demonstrated that ARF exert a tumor-suppressive function by activating the p53 downstream pathways through inhibiting the ubiquitin ligase MDM2 and impeding the ARF-BP1/Mule-mediated p53 degradation process (Chen et al. 2005; Sherr 2006; Zindy et al. 1998). The gene discussed is TP53; the disease is neoplasm.