To determine the role Ng2/Cspg4 plays in sarcoma tumor growth and maintenance, we employed a dual recombinase system by crossing Ng2/Cspg4f/f mice with KrasFRT-STOP-FRT-G12D/+; p53FRT/FRT; Rosa26Cre-ER-T2/+ mice to generate KrasFRT-STOP-FRT-G12D/+; p53FRT/FRT; Rosa26Cre-ER-T2/+; Ng2/Cspg4f/f mice (KPRNG2). The gene discussed is FLT1; the disease is sarcoma.