Fig. 2From: Enhancing the interferon-γ release assay through omission of nil and mitogen valuesSpearman’s rank correlation analysis of the IFN-γ levels of the Nil and TBAg in all subjects (a) and in the active TB (b), IGRA-positive non-TB (c), and IGRA-negative non-TB (d) groups. IFN-γ interferon-γ, Nil nil tube, TBAg tuberculosis antigen tube, TB tuberculosis, IGRA interferon-γ release assay, non-TB non-tuberculosisBack to article page