This may include endogenous IFN-γ, providing an explanation for the low plasma IFN-γ in patients with AD IFN-γR1 deficiency, while IFN-γ plasma levels in AR IFN-γR1 are typically either moderate (partial deficiency) or high (complete deficiency) (5, 6). This evidence concerns the gene IFNG and hyperinsulinemic hypoglycemia, familial, 4.