The enhanced oncogenic GOF potential of p53 mutants, beyond the loss of p53 function, is best exemplified by studies using mice with point mutations (p53R270H/- and p53R172H/) as models for the human Li-Fraumeni syndrome, which is an autosomal dominant inherited cancer susceptibility disorder resulting from germline mutations in the TP53 gene (14, 18–21). Here, TP53 is linked to Li-Fraumeni syndrome.