IFNG and immunodeficiency disease: Impaired B cell maturation Khan et al. (1997); Defective Ig class switching and GC formation causing immunodeficiency Locksley et al. (2001); succumbed to low-dose aerosol infection with M. Tuberculosis due to deficient IL-12 production leading to impaired priming of IFN-gamma T cell responses Ishikawa et al. (2005)