IL17F and chronic mucocutaneous candidiasis: This is corroborated by the clinical observation that immunodeficient patients with defects in IL-17A and IL-17F signaling due to genetic deficiency of the IL-17 receptor subunit IL-17RA, deficiency in IL-17F or mutations in the downstream adaptor protein NFκB activator 1 (ACT1) often suffer from chronic mucocutaneous candidiasis (CMC) [165–167].