ALK and Ewing sarcoma: Amplification of the ALK locus and consequent overexpression of ALK protein has been reported in many different types of cancer cell lines and human tumor samples [16, 24] including melanoma, NSCLC, neuroblastoma, glioblastoma, rhabdomyosarcoma, ovarian cancer, breast cancer, astrocytoma, Ewing’s sarcoma, and retinoblastoma.