While homozygous mutations of the p53 gene are lethal in the embryonic state, heterozygous mutations of p53 cause Li-Fraumeni syndrome (LFS), associated with predisposition to rhabdomyosarcoma, but also to multiple cancers such as in muscles, breast, bones, and blood cancers [221,222]. The gene discussed is TP53; the disease is hematopoietic and lymphoid system neoplasm.