TLR4 and necrotizing enterocolitis: showed that TLR4 activation occurs during NEC, an endogenous TLR4 ligand, high mobility group box 1 (HMGB1) is released from the intestinal and activates TLR4 on microglia, leading to the accumulation of reactive oxygen species (ROS), loss of oligodendrocyte progenitor cells (OPCs), dysmyelination, and cognitive impairments.