Extracellular antigens are limited in sarcomas overall, with a few exceptions of GD2 in osteosarcoma, rhabdomyosarcoma, and Ewing’s sarcoma; platelet-derived growth factor receptor α in rhabdomyosarcoma and HER-2 in osteosarcoma[48,73,74]. Here, ERBB2 is linked to rhabdomyosarcoma.