TP53 and Li-Fraumeni syndrome: Furthermore, female patients with germline p53 mutations (Li-Fraumeni syndrome [LFS]) are especially prone to the Her2 subtype of breast cancer (up to 83% of all breast cancer in LFS women [5, 6] compared to 20% in sporadic breast cancer [1]), suggesting cooperative co-selection of these potent oncogenes during Her2 breast cancer progression.