The microenvironment in myelodysplastic syndromes: niche-mediated disease initiation and progression.

•Microenvironmental defects can initiate myeloid neoplasms, including myelodysplastic syndrome (MDS).•MDS induces functional alterations in microenvironmental cells.•Niche abnormalities impair normal hematopoiesis and facilitate MDS progression.•Aberrant inflammatory signaling contributes to pathologic features of MDS.•Vascular and endothelial abnormalities may contribute to MDS progression.