IFNG and tuberculosis: It has been shown that KIR B is associated with higher IFN-γ release from NK cells upon stimulation with mycobacteria in vitro (Portevin et al. 2012), and multiple studies of KIR genes in tuberculosis patients suggest that greater NK cell inhibition is a risk factor for the disease (Braun et al. 2013; Mahfouz et al. 2011; Méndez et al. 2006; Shahsavar et al. 2012) [although not every tuberculosis study has found an effect (Tajik et al. 2012)].