IDO1 and chlamydia trachomatis infectious disease: These genes were selected for the following hypothetical implications; indicative of a pro-inflammatory response needed to clear chlamydial infections (CXCL-9, IFN-γ, TNF-α, IRF-1, IL-8, IL-1α); biological role which may implicate host conditions compatible with chlamydial persistence (IDO-1, FTH-1); pleiotropic or reduced pro-inflammatory responses (IL-10 and IL-6) (50–52).