TP53 and Li-Fraumeni syndrome: Somatic mutations in TP53 gene are the most common genetic alterations found in human cancers, such as breast and bladder cancer, head and neck squamous carcinoma, lung cancer, melanoma, ovarian cancer and many others, as well as Li-Fraumeni syndrome (LFS) that is associated with inherited mutations in TP53 gene and hereditary cancer predisposition [18].