↑ IL-1β, TNF-α, soluble TNF receptor (sTNFR)1, IL-12, and IL-10 in MDD vs. BD↑ IL-6, sTNFR2, IL-18, IL-33, ST2 (IL1R Like 1), and Klotho in BD vs. MDDIL-1β levels in MDD patients with melancholic features (vs. without melancholia)sTNFR1/sTNFR2 ratio predicted MDD and state and trait anxiety and negative affect. The gene discussed is KL; the disease is major depressive disorder.