“…Patient-derived xenografts (PDX) and all Ewing sarcoma cell lines were described. 24 All EWS cell lines [ES1 (RRID: CVCL_1198), ES2 (RRID: CVCL_AX39), ES4 (RRID: CVCL_1200), ES6 (RRID: CVCL_1202), ES7 (RRID: CVCL_1203), ES8 (RRID: CVCL_1204), SKNEP1 (RRID: CVCL_0631), TC71 (RRID: CVCL_2213) and CHLA258 (RRID: CVCL_A058), and EW8 (RRID: CVCL_V618)] were maintained in RPMI supplemented with 10% FBS, 0.1 mM nonessential amino acids, sodium pyruvate, penicillin, streptomycin, L-glutamine (Thermo Fisher Scientific, Waltham, MA). GD2 negative A204 (RRID: CVCL_1058) rhabdomyosarcoma cells were purchased from ATCC (American Type Culture Collection, Manassas, VA) and were transduced with a gammaretroviral cassette coexpressing GD2 and GD3 synthases (Addgene, Plasmid #75013) to drive the biosynthesis of GD2 as described.…”