Macrophages are myeloid immune cells that are strategically positioned throughout the
body tissues, where they ingest and degrade dead cells, debris, and foreign material and
orchestrate inflammatory processes. Here we review two major recent paradigm shifts in our
understanding of tissue macrophage biology. The first is the realization that most tissue-
resident macrophages are established prenatally and maintained through adulthood by
longevity and self-renewal. Their generation and maintenance are thus independent from …