Next generation sequencing studies have revealed a large number of mutations in genes such as TET2, CBL, AXSL1, RUNX1, EZH2, RAS, JAK2, IDH1/IDH2, NPM1 and spliceosome mutations in CMML [18] as well as CSF3R, SETBP1 mutations in CNL and aCML [19]. Here, TET2 is linked to atypical chronic myeloid leukemia, BCR-ABL1 negative.