The genomic landscape of CMML includes mutations affecting DNA methylation (TET2, DNMT3A), RNA splicing (SRSF2, SF3B1, U2AF1, ZRSR2), signal transduction (NRAS, KRAS, CBL, PTPN11, JAK2), as well as transcription factors and nucleosome assembly (SETBP1, RUNX1) [1]. This evidence concerns the gene SF3B1 and chronic myelomonocytic leukemia.