1 Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA.
2 Department of Medicine, University of California San Diego, La Jolla, CA 92093, USA; Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, CA 92161, USA. Electronic address: changj@ucsd.edu.
In this issue of Immunity, Hirai et al. illuminate competition for the cytokine TGFβ as a key regulator of CD8+ tissue-resident memory T cell persistence and occupancy in the skin epidermal niche.