Compared to healthy donors, CD8+ T cells in sarcoidosis patients had increased activity, indicated by elevated expression of cytotoxicity‐related genes (GNLY, NKG7, GZMB, PRF1, ZEB2 and KLRG1), cytokines (TNF, IFNG and TGFB1), chemokine ligands (CCL3, CCL4 and CCL5) and S100 family proteins (S100A4, S100A6, S100A10) (Figure 3h). Here, PRF1 is linked to sarcoidosis.