The ability of the p53 R270H mutation to drive CaP initiation in this setting, and the timing of PIN lesion incidence and PIN lesion grade aligns with what was observed by our group in a different Trp53 R270H GEM (FVB.129S4 (Trp53tm3Tyj); FVB.129S (Nkx3-1tm3(cre)Mms)). In our prior study, pre-PIN atypia and grade one PIN lesions were observed in homozygous mice as early as 5 weeks (note that this time point was not assessed in the current study) and grade three to four PIN lesions were observed at 6 months of age (compared to 5 months in the current model). Here, TP53 is linked to prostate intraepithelial neoplasia.