TET2 and myelodysplastic syndrome: Additionally, a comparative study of somatic mutation profiling of CD34+, HSCs, and circulating endothelial cells (CECs) revealed that in 70% of patients with MDS—both CECs and HSCs—harbor the most frequently mutated genes, such as JAK2, ASXL1, TET2, NOTCH1, and SRSF2 [76].