A functional deficiency in the Th17 cell subset is associated with a dysbiotic state characterized by Candida overgrowth.14 Furthermore, signalling through the IL-17 receptor is crucial for protecting against candidiasis.47 The results of these studies demonstrated that IL-17 can play a central role on influencing the composition of core fungi, such as Candida and Aspergillus. The gene discussed is IL17A; the disease is candidiasis.