Individuals with a low BMI have decreased levels of proinflammatory cytokines (IFN-γ, TNF-α, IL-22, IL-1α, IL-1β, and IL-6) but increased levels of regulatory cytokines (IL-10, TGF-β, IL-5, and IL-13) (21), suggesting a potential biological mechanism by which BMI regulates the severity of TB through immune modulation. This evidence concerns the gene IL1A and tuberculosis.