Patients with no mutations identified underwent reanalysis in an extended gene panel of Inborn Errors of Immunity, which led in 42 cases to the diagnosis of neutrophil dysfunction, innate immune disorders, or autoimmunity-related syndromes such as APS1, CTLA4 deficiency, CVID, or ALPS, which may develop a more expressed phenotype with age. The gene discussed is CTLA4; the disease is hyperinsulinemic hypoglycemia, familial, 4.