Deletions at Trp53 and Nf1 loci established a genetic link to human soft-tissue sarcomas, which are characterized by frequent p53 mutations [34]–[36], as well as to syndromes associated with increased RMS incidence due to germ-line disruption of these tumor suppressor genes (Li-Fraumeni, TP53; Neurofibromatosis type I, NF1) [37]. This evidence concerns the gene TP53 and soft tissue sarcoma.