XIAP and hyperinsulinemic hypoglycemia, familial, 4: The 12-year-old hyper-IgE syndrome patient (patient 5) presented approximately twice as many PIWIL4+ cells as the XIAP deficiency patient (patient 6), while the 7-year-old ß-thalassemia major patient whose tissue was applied for the organ culture had the highest PIWIL4+ cell count (Figure 6h, patient 2).