CDKN1B and Familial prostate cancer: In prostate cancer, TGF-β-mediated apoptosis involves: (i) caspase 1 activation 80; (ii) up-regulation of pro-apoptotic factors (e.g. Bax, p27KIP1); and/or (iii) down-regulation of antiapoptotic factors (e.g. Bcl-2 and Bcl-xl) 51,81 (Fig. 2).