Compared with that of Ptch1+/−p53∆E5-6/ΔE5-6 mice, survival of Ptch1+/−p53ΔE5-6/R172P mice was extended by 26%, demonstrating p53R172P tumor suppressive activities (82 days, P < .0001) (Figure 1B; Supplementary Figure S1A). This evidence concerns the gene PTCH1 and neoplasm.