TLR4 and diabetes mellitus: A recent study showed that oxidative stress (ROS and H2O2) promoted the expression of Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) in human periphery monocytes to increase the expression of cytokines, such as IFN−gamma, IL−1 beta, IL−6, etc., in diabetes mellitus (DM) [41].