The p53 mutant mice exhibited a similar tumor profile as ESC-based p53 KO mice reported previously17,18; however, the brain tumors that were previously observed only in heterozygotes of ESC-based p53 KO mice were observed in our homozygous p53 mutant mice (2 out of 21 mice with tumor) (Supplementary Table 5). This evidence concerns the gene TP53 and brain neoplasm.