IL2 and tuberculosis: The choice of setting the LIOSpot® TB assay on IL-2 cytokine production is due to the fact that recent studies demonstrate the importance of this cytokine to discriminate between latent and active tuberculosis infection, thus being a new possible diagnostic biomarker [35, 36, 37, 38]; based on the fact that IL-2 is significantly differentially produced by individuals with LTBI and active TB patients [37, 39, 40].