CD4 and congenital secretory chloride diarrhea 1: Consistent with greater SenMayo enrichment in skeletal muscle (Fig. 2), the CLD cohort had significantly greater proportions of senescent CD8+ T cells (p = 0.013), exhausted CD4+ T cells (p = 0.0003), and regulatory T cells (p = 0.0001), which are all markers of an aged immune system.