STAT3 and Alzheimer disease: Autosomal dominant STAT3 deficiency (AD-STAT3) is a multi-system disorder characterized by severe neonatal eczema, “cold” staphylococcal abscesses, recurrent bacterial respiratory tract infections that may lead to bronchiectasis or pneumatoceles, mucocutaneous candidiasis, eosinophilia, and markedly elevated IgE.