Guardian of two galaxies: Senescence-associated immune cells control disease tolerance and aging.

Preservation of host fitness is a common feature of longevity and immunity to infection. In this issue of Immunity, Triana-Martinez et al. reveal that p16High senescence-associated immune cells promote disease tolerance and healthy aging. Mechanistically, this is dependent on Toll-like receptor 7 (TLR7) and stimulator of interferon genes (STING) innate immune signaling controlling adenosine concentrations.