As reported for WAS and WAS-like conditions, several IPEX-like syndromes have been described in the last years,116 including CD25 deficiency, STAT5b deficiency, and Itchy E3 Ubiquitin Protein Ligase (ITCH) deficiency [Table 3]. The gene discussed is STAT5B; the disease is hyperinsulinemic hypoglycemia, familial, 4.