PD-L1 was significantly over-represented in whole blood from active TB patients as compared with healthy controls and latent TB patients in three independent cohorts of patients (Fig. 1A); two recruited in London (Training and Test sets, p=0.0043 and 0.000521, respectively) and one from a TB endemic area (South Africa; validation set, p<0.0001). This evidence concerns the gene CD274 and tuberculosis.