To select an appropriate dose of dasatinib for our assays, dasatinib IC50 values (half maximal inhibitory concentration) for PDGFRB inhibition in Ewing sarcoma cell lines have not been reported, but respective IC50 values for SRC reached up to 50 fold above references [38, 41], implying relative resistance. The gene discussed is SRC; the disease is Ewing sarcoma.