Not all published studies have supported activity of mTOR inhibition in osteosarcoma; prior combinations of rapamycin with cyclophosphamide and temsirolimus with the insulin-like growth factor-1 receptor (IGF-1R) antibody cixutumumab failed to demonstrate efficacy in phase II studies including recurrent osteosarcoma patients21–23. The gene discussed is IGF1R; the disease is osteosarcoma.