miRNAs and megakaryocytopoiesis. This diagram summarizes the miRNAs known to participate in megakaryocytopoiesis. Megakaryocytes (MK) originate from self-renewing HSC, which differentiate progressively into common myeloid precursors (CMP), MEPs, and megakaryocyte precursors (MP). The height of the triangles indicates the level of the miRNA, with some miRNAs decreasing during megakaryocytopoiesis, and others increasing. There is conflicting evidence regarding the role of miR-146a. Levels of miR-125b-2 do not change during progression from MEP to MP.