To determine the anti-tumorigenic effect of CD99CRIII3 and the importance of PTPN12 in suppressing tumor progression, we generated a stable MDA-MB-231 cell line (shPTPN12-MDA-MB-231) with 75% reduction in PTPN12 protein using the shRNA system (Figure S7A). The gene discussed is PTPN12; the disease is neoplasm.