IGF1R and osteosarcoma: Using a class of fully humanized anti-IGF-1R Ab, made possible through recombinant technologies, unexpectedly high clinical response rates for sarcoma subtypes (specifically EWS and osteosarcoma) have renewed academic interests in IGF-1R targeted therapies and, consequently, nearly a dozen phase I/II trials are currently underway evaluating IGF-1R targeted monoclonal antibodies (mAb) or small molecules for the treatment of EWS [84,85].