Thymic lymphopoiesis depends on blood-borne, marrow-derived progenitors, but characterization of these cells, and their lineage potentials, has been difficult. In this issue, Krueger and von Boehmer (2007) show some blood cells that are already T lineage restricted, suggesting that T lineage commitment can occur prethymically. © 2007 Elsevier Inc. All rights reserved.
Petrie, H. T. (2007, January). Early Commitment: T Cell Progenitors in the Blood. Immunity. https://doi.org/10.1016/j.immuni.2007.01.003