PAX3 and alveolar rhabdomyosarcoma: Alveolar rhabdomyosarcoma (ARMS)—an invasive subtype of rhabdomyosarcoma—is characterised by fusion of Pax3 or Pax7 genes on chromosome 1 and 2, respectively, with the FOXO1 gene; which encodes Pax3-FOXO1 and Pax7-FOXO1 fusion proteins [29].