CD274 and tuberculosis: Thus, we observed that the expression of PD-L1 in CD14+ cells from pleural effusion mononuclear cells (PEMC) was highly increased compared to PBMC CD14+ cells from TB patients and also to peripheral CD14+ cells from individuals with latent TB or healthy donors, both in terms of the expression level on a per-cell basis or the percentage of positive cells (Fig. 1A).