Confirmed cases of C4BP deficiency have not yet been reported in humans. Only one human case has been reported of the primary C4BP deficiency in a patient with disease clinically resembling Behçet’s disease with angioedema (69), but it is not clear whether the complete disease was associated with C4BP deficiency or just the angioedema. This evidence concerns the gene C4BPB and hyperinsulinemic hypoglycemia, familial, 4.