IFNG and infection: Furthermore, using MC-deficient KitW-sh/KitW-sh mice for infection with L. major promastigotes results in a worse disease outcome, e.g., significantly enhanced lesion progression and lesional parasite burdens, accompanied by significantly decreased levels of IFN-γ and IL-17A, but significantly increased IL-4 and IL-10, compared to wild-type mice, indicating that MCs play a crucial role against Leishmania parasites by promoting Th1 and Th17 responses in vivo (26).