ARMS is most commonly characterized by the presence of a t(2;13) (q35;q14) (~60%) or a t(1;13) (p36;q14) (~20%) chromosomal alteration, generating the PAX3-FOXO1 (Barr et al., 1993; Shapiro et al., 1993) or PAX7-FOXO1 (Davis et al., 1994) oncogenic fusion proteins, respectively. This evidence concerns the gene FOXO1 and alveolar rhabdomyosarcoma.