JAK2 and acute lymphoblastic leukemia: In agreement with previous descriptions of Ph-like BCP ALL, most cases (11/15, 73%) harboured gene fusions that deregulate the cytokine receptor CRLF2 (P2RY8-CRLF2, n=6; and IGH-CRLF2, n=3) or activate therapeutically targetable kinases (ZC3HAV1-ABL2 in #62 and PAX5-JAK2 in #45) (refs 7, 8;, Supplementary Data 3).