IL17A and infection: On the other hand, LL with ENL showed an increase in IL-17.[33,56] IL-17 also plays a role in the early infection and prevention of leprosy, as study find out that healthy household contacts with a long-term exposure to patients have a higher expression of IL-17 compared with unexposed individuals.[57] IL-17 as a sensitive biomarker for TL type may helpful for leprosy monitoring and treatment.