PAX5 and acute lymphoblastic leukemia: In the BCR-ABL1-like subgroup we also identified 3 patients harboring a P2RY8-CRLF2 fusion, which is associated with poor prognosis in children [56], and 3 patients with fusions involving PAX5. Cases harboring PAX5 or CRLF2 fusions have been proposed as an independent subgroup in BCP-ALL [2].