In sarcoidosis, fluorescence measurement further revealed compartment-specific differences of TIGIT, but not of PD-1 expression; TIGIT levels were significantly higher in T cells (including CD4+, CD8+, and FOXP3+) in the intergranulomatous area as compared to the granulomas (p < 0.05, Figure 3). This evidence concerns the gene CD4 and sarcoidosis.