Here, we aimed to investigate differences in microRNA expression profiles for negatively regulating TLR4 signaling including let-7e, miR-21-5p, miR-223, miR-145, miR-146a, and miR-155 in PBMCs and monocytes, which showed altered patterns of response to endotoxin challenge in depressed patients [10] from patients with MDD before and after treatment with antidepressants. The gene discussed is TLR4; the disease is major depressive disorder.