The JAK2 inhibitor, ruxolitinib, has been shown to reduce tumor burden in xenograft mouse models harboring BCR-JAK2 [t(9;22)(p24;q11.2)] [88], and has demonstrated promising results in the treatment of CRLF2-rearranged, JAK2-mutated leukemic cells in vitro [87]. This evidence concerns the gene JAK2 and neoplasm.