Commercially available IFN-gamma (IFN-γ) release assays (IGRAs) such as Quanti-FERON-TB Gold have been developed successfully for specific detection of M. tuberculosis infection and discrimination from all (nonvirulent) BCG strains and most other nontuberculous mycobacteria (NTMs) [7], which has inspired research into the feasibility of developing similar peptide-based assays for the identification of asymptomatic leprosy [6]. This evidence concerns the gene IFNG and leprosy.