CRLF2 and acute lymphoblastic leukemia: Preclinical studies on adverse-risk Ph-like ALL, which frequently harbors Janus kinase (JAK) and cytokine receptor-like factor 2 (CRLF2) mutations, indicate sensitivity to JAK inhibition and mammalian target of rapamycin (mTOR)/PI3K inhibitors 10, 16, 17, whereas platelet-derived growth factor beta (PDGFB)- and ABL-rearranged Ph-like disease instead appear to display responsiveness to the tyrosine kinase inhibitors imatinib and dasatinib 8, 18, 19.