IFNG and infection: When a host detects the presence of TB bacteria, certainimmunecells, such as T helper cells, release the interferon-γ (IFN-γ)cytokine as part of the hosts defense mechanism.62 This happens because IFN-γ is required to activateother immune cells, such as macrophages, to coordinate their effortsto combat the infection.63 Consequently,the production of IFN-γ in response to the TB bacteria makesit a valuable diagnostic marker.