AXL and osteosarcoma: To investigate the expression of AXL on sarcoma cells (Figure 1A), we collected a panel of seven human cell lines, including CAL-72 (osteosarcoma), ESS-I (endometrial stromal sarcoma), HT-1080 (fibrosarcoma), SAOS-2 (osteosarcoma), Rh-30 (rhabdomyosarcoma), SW982 (synovial sarcoma) and RD-ES (Ewing’s sarcoma).