While our data suggest that RP-Mdm2 signaling does not inhibit APT121-induced prostate cancer, previous findings have shown that both RP-Mdm2 and p19Arf-Mdm2 signal to p53 and function equivalently as barriers to suppress Myc-induced B cell lymphoma [11], [19]. This evidence concerns the gene MDM2 and Familial prostate cancer.