Bone marrow samples from del(5q) MDS patients display increased apoptosis associated with increased expression of TP53 and its target genes in erythroid cells.32, 33 During the early stage of erythropoiesis, hematopoietic stem cells sequentially give rise to the common myeloid progenitor, megakaryocyte-erythrocyte progenitor, burst-forming unit-erythroid, and colony-forming unit-erythroid cells.34 The gene discussed is TP53; the disease is myelodysplastic syndrome.