IDO1 and Granuloma: Therefore, to evaluate the specificity of macrophage PD-L1 and IDO1 expression in Mtb infection, we used immunohistochemistry (IHC) to compare both proteins on a tissue microarray of granulomas from sarcoidosis (n = 9), foreign body uptake (n = 4), endometriosis (n = 4) and xanthomatosis (n = 3) (Extended Data Fig. 7e).