Postabsorptive GIP concentrations did not differ between T2D (10.0 [8.5, 13.3] pmol/L and 12.0 [11.0, 13.0] in RYGB and SG, respectively) and control subjects (9.0 [8.5, 10.5] pmol/L, p = 0.500), and during the OGTT, GIP concentrations increased comparably before and after surgery in all groups. The gene discussed is GIP; the disease is type 2 diabetes mellitus.