During infection or injury, degradation of high-molecular weight HA (HMW-HA) to low-molecular weight HA (LMW-HA) by host hyaluronidases and reactive oxygen species (ROS) is thought to stimulate proinflammatory responses mediated by TLR2 and TLR4 signaling (11, 12). This evidence concerns the gene TLR4 and infection.