Mutations in the genes implicated in various cellular pathways were identified in most MDS cases and during disease evolution [36] and will be discussed as follows: RNA-splicing factors (for example SF3B1, ZRSR2, SRSF2, U2AF1), epigenetic regulators (such as DNMT3A, TET2, IDH1, IDH2, ASXL1, and EZH2), transcription factors (for example RUNX1, ETV6, GATA2, BCOR), cell-cycle regulators (for example, TP53, CDKN2A), cell-signaling molecules (for example, NRAS, KRAS, PTPN11, CBL, JAK2, FLT3), as well as other mutations (for example in NPM1 gene). The gene discussed is TET2; the disease is myelodysplastic syndrome.