Then, 1 month after infection, there is a progressive immune-regulation mediated by Th-2 cells and high production of anti-inflammatory cytokines, such as IL-10 and TGF-β, that in coexistence with a decrease in the production of Th1 cytokines, progressive pneumonia, and high bacillary load, produce animal’s death (Hernández-Pando et al., 2008). This evidence concerns the gene TGFB1 and infection.