Circulating CD4+T cells are reduced in sarcoidosis, likely reflecting a combination of recruitment to sites of inflammation, increased apoptosis, and disrupted homeostatic regulation.74, 88, 139, 140Functionally, both naïve and effector T cell subsets exhibit alterations suggestive of systemic immune dysregulation that contributes to sarcoidosis. Here, CD4 is linked to sarcoidosis.