The B cell precursor leukemia cell line MUTZ-5 from a relapsed Philadelphia-like B-ALL patient features a CRLF2-translocation leading to wt CRLF2 overexpression, as well as the JAK2R683G mutation, and the absence of mutations in any RAS-MAPK pathway genes [26]. Here, CRLF2 is linked to acute lymphoblastic leukemia.