TNF and major depressive disorder: Literature studies have found that the occurrence, development, and treatment of depression are related to relaxin signaling pathway [77], MAPK signaling pathway [78], endocrine resistance [79], AGE-RAGE signaling pathway in diabetic complications [80], HIF-1 signaling pathway [81], dopaminergic synapse [82], focal adhesion [83], cAMP signaling pathway [84], TNF signaling pathway [85], Ras signaling pathway [86], and neuroactive ligand-receptor interaction [87].