Figure 2.

An illustration depicting the two waves of hematopoiesis during prenatal human development; the primitive wave of haematopoiesis occurs in embryonic life and the second wave of definitive haematopoiesis occurs in fetal life. During the primitive wave, progenitors from the yolk sac (YS) and aorta‐gonad‐mesonephros (AGM) seed the liver, bone marrow (BM), and peripheral tissues. During the definitive wave, blood and immune cells and progenitors further colonize firstly the BM, from the liver and then the peripheral organs from both the liver and BM. Arrows represent the movement of cells. Illustration created with BioRender.com.