CD8A and thymus atrophy: First, CD4 TSCM frequencies demonstrated an even more pronounced age-associated trend than observed for TNAIVE cells (p < 0.0001, n = 43 and n = 166 for young and older donors, respectively, Fig. 2a), the latter may be linked to thymic atrophy as shown by the peripheral decrease of TRTE during aging (Supplementary Fig. 1B, C); we observed a similar trend for CD8 T cells (p < 0.0001, Supplementary Fig. 1D).