Patients with autosomal-dominant hyper-IgE syndrome (AD-HIES) harbor loss-of-function (LOF) mutations in the STAT3 gene.86,87 In turn, a severe dysbiosis of fungal community was found in AD-HIES patients’ oral mucosa, with a dominance of C. albicans and minimal representation of health-associated fungi.85 The STAT3 defect in participants with AD-HIES was also associated with distinctive bacterial communities, particularly with a reduced microbial diversity and an enrichment of Streptococcus oralis and S. mutans. Moreover, increased abundance of cariogenic bacteria—S. Here, STAT3 is linked to Alzheimer disease.