While MET is a hallmark of tissue granuloma formation,1, 7 blood monocytes in both active TU and sarcoidosis exhibited epithelial–mesenchymal transition (EMT) signatures (Figure 4e), including significantly increased expression of GADD45B, CD44, CXCL8, ANPEP and THBS1,30, 31, 32, 33 compared with healthy donors (Figure 4g). Here, CXCL8 is linked to sarcoidosis.