IFNG and infection: The current literature contains a few studies on the polymorphisms of the IFN-γ gene in the pathogenesis of various diseases—primarily viral and bacterial – but to our best knowledge, our study is the first to address the impact of IFN-γ gene polymorphisms in the context of the immune response to T. pallidum infection, the persistence of infection, and the occurrence of the serofast state in syphilis.