GSTM1 and tuberculosis: Using the dual combination of a low blood Hb (below the normal reference value for males and females, respectively) with a low BMI (underweight ≤ 18.5), it was revealed that less than 10% of mild TB patients, but more than 40% of patients with moderate-severe TB disease, expressed this combination (χ2 = 122, d.f. = 2, p < 0.0001) (Figure 1I).