TET2 and myelodysplastic syndrome: The most common mutations seen in MDS include those involving spliceosome function such as SF3B1 (24.5%), SRSF2 (11.8%) and U2AF1 (6.6%), mutations involving DNA methylation such as TET2 (22.9%) and DNMT3A (10.3%), and histone modification such as ASXL1 (12.9%).