The pathogenic potential of Mycobacterium tuberculosis(Mtb), the etiologic agent of human tuberculosis (TB), dependslargely on the type VII secretion system ESX-1 [1,2],which is responsible for the secretion of the 6-kDa Early Secreted Antigenic Target(ESAT-6), its protein partner, the 10-kDa Culture Filtrate Protein (CFP-10), and severalESX-1 associated proteins (Esps) [3,4]. The gene discussed is ESX1; the disease is tuberculosis.