To further corroborate the effect of p53 loss on tumorigenesis in prostate cancer development and progression, we used a second murine model, the Pbsn-Cre model, and examined prostate tumorigenesis phenotypes of the Pbsn-Cre; Trp53LoxP/LoxP; ETV4AAA and Pbsn-Cre; Trp53LoxP/+; ETV4AAA GEM model with homozygous and heterozygous Trp53 deletion at 6, 9, and 12 months of age. The gene discussed is TP53; the disease is Familial prostate cancer.