Tissue-resident macrophages have pivotal functions for tissue defense and homeostasis.
Two main discoveries have changed our current understanding of macrophage
development: Their embryonic origin and their ability to self-renew throughout the lifespan. It
is now well accepted that most tissue-resident macrophages are long-lived cells derived
from a transient hematopoietic wave of erythro-myeloid progenitors (EMPs) emerging in the
yolk sac. At least two distinct pathways derived from EMPs have been implicated in …