CTSK and sarcoidosis: Sarcoidosis samples showed higher expression of genes with putative roles in granuloma formation, including cathepsin K, transmembrane 7 superfamily member 4, and chemokine (C-C motif) ligand 21.27, 28, 29 We hypothesize that this may reflect the more organized, noncaseating granuloma phenotype typical of sarcoidosis.30