LAUSR

T Cells When T cells take up residence in a tissue, adaptation to that tissue is key for their survival. Frizzell et al. studied metabolic adaptation of tissue-resident memory T (TRM) cells at three different sites: skin, liver, and small intestine. They found that TRM cells in each kind of tissue rely on distinct members of the fatty acid–binding protein (FABP) family of proteins for uptake of fatty acids. By transferring liver-resident TRM cells into naive mice, they found that FABP expression of these TRM cells was reprogrammed by the tissue they ended up seeding in the recipient mice. This study reinforces the idea that immune cells are integral components of the tissues in which they reside. Sci. Immunol. 5 , eaay9283 (2020).