IFNG and tuberculosis: Further evidence for the role of IFNG comes from the characterization of several types of primary immune deficiencies in which mutations in the IFNG receptor were shown to confer Mendelian susceptibility to mycobacterial disease, i.e., susceptibility to non-TB mycobacterial infections (Newport et al., 1996) or to disseminated BCG disease (Jouanguy et al., 1996).