Current literature supports a hierarchical model of hematopoiesis with gradual transition between cellular nodes reflecting increasing priming toward particular lineages and gradual loss of multipotency. Lineage-primed and unipotent cells may exist within multipotent HSC/MPP populations. CLP, common lymphoid progenitor; EoMP, eosinophil-basophil-mast cell progenitor; LMPP, lymphoid-primed multipotent progenitor; MyeP, myeloid progenitor. Professional illustration by Patrick Lane, ScEYEnce Studios.