The lack of reported malignancies in LRBA deficiency may result of the fact that the phenotype of LRBA deficiency is usually even more severe than that of CTLA-4 insufficiency and patients either die at an early age or receive HSCT, possibly prior to the development of any malignancy. The gene discussed is CTLA4; the disease is hyperinsulinemic hypoglycemia, familial, 4.