RYGB improves glucose regulation independent of 5-HT2CR signaling. Fasted glucose (A), fed glucose (B), fasted insulin (C), fed insulin concentrations (D), and HOMA-IR (E) measures in diet-induced obese WT and 5-HT2CR-deficient mice 10–11 weeks after RYGB or sham operations (n = 4–6 per group). *, P < .05; **, P < .01; ***, P < .001. Values represent the mean ± SEM.