In 2011, Liu et al. and van de Veerdonk et al. demonstrated that an enhanced STAT1 activity, as a result of heterozygous GOF mutations of STAT1, was also deleterious, presenting with a chronic mucocutaneous candidiasis (CMC) phenotype due to impaired IL-17 immunity (18, 19). This evidence concerns the gene IL17A and chronic mucocutaneous candidiasis.