CRLF2 and cancer: The involvement of USP9X and DDX3X in cancer is known39, 40, 41, 42, 43, 44, 45 and another translocation involving USP9X has been reported in a BCR‐ABL1‐like ALL patient without CRLF2‐r.4 In keeping with the emerging functions of USP9X, its overexpression has been reported in B‐ALL, suggesting an oncogenic role.46 Knockdown of USP9X sensitises both prednisolone sensitive and resistant cell lines to glucocorticoid (GC)‐induced apoptosis, suggesting that reduced levels of USP9X may sensitise them to prednisolone treatment.46