MDSC enriched in TB patients, according to recent recommendations using a ficoll density-gradient (22, 23), have been classified as e-MDSC (LIN1−HLA-DR−/loCD11b+CD33+), PMN-MDSC (HLA-DR−/loCD11b+CD14−CD15+CD33+/dim) and M-MDSC (HLA-DR−/lowCD11b+CD14+CD15−CD33+) (20). Here, CD33 is linked to tuberculosis.