To evaluate the anti-pre-B ALL activity of GZD824 in vivo, we generated human pre-B ALL PDX models by transplanting splenic pre-B ALL cells from the five patient-derived (Supplementary Table S1) xenograft mouse lines into NOD-scid-IL2Rg−/− (NSI) mice [18–21]. This evidence concerns the gene IL2RG and acute lymphoblastic leukemia.