TP53 and prostate carcinoma: Arrest in the G1 phase was also observed in prostate cancer studies, without involvement of p53 (Gupta et al., 2003), while in leukemic cells the apoptotic effects were mediated through p53, p21 and Bax (which showed increased expression) and down-regulation of Bcl-2-α (Harakeh et al., 2008).