GSTM1 and tuberculosis: Accordingly, IL-6 levels correlated with the clinical TB score (r = 0.49, p < 0.0073) but were inversely correlated to blood Hb (r = −0.56, p < 0.0017) and IFN-γ (r = −0.48, p < 0.0144) (Figure 5F,G).