STAT3 and hyperinsulinemic hypoglycemia, familial, 4: STAT3 deficiency and DOCK 8 deficiency are rare phenotypes of primary immunodeficiency that feature elevated serum IgE, eosinophilia, susceptibility to cutaneous and sinopulmonary infections, predisposition for malignancy (predominantly lymphoma), and eczematous dermatitis [69,70,71].