Proposed model for human hematopoiesis. The classical model of hematopoiesis was based in hierarchical and sequential differentiation from hematopoietic stem cells to mature cells. However, recent studies provide evidence that mature cells such as megakaryocytes could be derived directly from HSCs. We propose a model that there is more than one origin of megakaryocytes, likely dependent on need. We observed that the heterogeneous mixture of cells within the Lin⁻CD34⁺CD38⁻ population includes cells that can give rise to megakaryocytes directly. This is in addition to a strictly bipotent MEP population that gives rise to megakaryocytes and erythrocytes. Solid arrows, validated in the manuscript.