Conversely, Vδ2+ cells produced more TGF-β in PHI patients than in UT-CHI patients [PHI 3.8% (2.0–7.8), UT-CHI 0.7% (0.2–1.4), p = 0.0008] (Figure 4E). The gene discussed is TGFB1; the disease is congenital isolated hyperinsulinism.