After bariatric surgery, all plasma levels of inflammatory markers, including C-reactive protein (median change, −0.32 mg/dL [IQR, –0.57 to –0.16 mg/dL]; P < .001) and leptin (median change, −51.5 pg/mL [IQR, –68.0 to –38.4 pg/mL]; P < .001), were lower, whereas adiponectin levels were higher (median change, 0.15 μg/mL [IQR, –0.20 to 0.62 μg/mL]; P < .001), depressive symptoms were (partly) resolved (median change in Beck Depression Inventory score, −3 [IQR, –6 to 0]; P < .001), and physical activity level was higher (mean [SD] change in Baecke score, 0.7 [1.1]; P < .001). The gene discussed is LEP; the disease is major depressive disorder.