Aging affects the development and function of TCs and NKs (Pinti et al., 2016). We identified known T cell subsets, including CD4+, CD8+, CD4+CD8+, CD4−CD8− and proliferative T cells (mitotic T cells, T-mito), based on the expression of canonical lineage markers (Fig. S3H). The CD4+ T cells were subdivided into five classes: CCR7high CD69low naive CD4+ T cells (CD4 Naive); CCR7med CD69high CCR6− central memory CD4+ T cells (CD4 Tcm); CCR6+ effector memory CD4+ T cells (CD4 Tem); FOXP3+ regulatory T cells (CD4 Treg) and PDCD1+ exhausted CD4+ T cells (CD4 Tex) (Fig. S3I). The CD8+ T cells were subdivided into four classes: CCR7+ naive CD8+ T cells (CD8 Naive); GZMK+ effector memory CD8+ T cells (CD8 Tem); GZMB+ GNLY+ cytotoxic CD8+ TCs (CD8 CTL) and PDCD1+ exhausted CD8+ T cells (CD8 Tex) (Fig. S3J).