Molecular control of the identity of tissue-resident macrophages.

Macrophages are present in virtually almost all tissues, exhibiting highly heterogeneous phenotypes as a consequence of adaptation to local tissue environments. Tissue-resident macrophages perform specialized functions that are essential for the maintenance of tissue homeostasis, and abnormalities of their functions are linked to various pathologies. Recent advances have shown that tissue-specific transcriptional programs are responsible for functional specialization of macrophages in different tissues. Here, I discuss the molecular basis of tissue-resident macrophage specialization and how it is regulated by tissue environmental cues.