To analyze the serum leptin and LepRb concentration, we collected blood samples from 30 health donors (median age, 57; range, 29–79 years) and 21 depressive patients (median age, 54; range, 16–69 years) and 27 GC patients (median age, 59; range, 26–79 years). The gene discussed is LEP; the disease is gastric cancer.