In patients who are IFN-γ release assay (IGRA) positive but acid-fast bacilli negative, signatures of HLA-DR+IFN-γ+ CD4+ T-cells and CD45RA-CCR7-CD127-IFN-γ-IL-2-TNF-α+ CD4+ T-cells were able to distinguish between active TB and LTBI [115]. Here, CD4 is linked to tuberculosis.