Time and place: mapping human prenatal macrophages across tissues

In a recent Cell paper, Wang et al. characterized human immune cells at the single-cell level across 19 tissues and throughout prenatal developmental phases. This work revealed two new macrophage populations: microglia-like macrophages outside the central nervous system, notably in the skin where they interact with neural crest cells, and perivascular proangiogenic macrophages throughout embryonic tissues.