BCG is a well-known and the most widely used vaccine against tuberculosis (27) that acts directly on the immune system to augment cell-mediated and Th1-biased responses by several mechanisms such as; stimulating TLRs (28, 29), activating CTLs (30-32) and increasing the level of IFN-γ secretion (33, 34). The gene discussed is IFNG; the disease is tuberculosis.