TLR4 and glaucoma: Genes that are expressed in activated microglia are significantly increased in mouse and rat models of glaucoma, such as: major histocompatibility complex–II (MHC-II), highly involved in the adaptive immune response; complement 1 complex components, involved in the innate immune response; P2Y12, the receptor responsible for initiating microglial migration to sites of damage; and TLR4, also involved in the innate immune response [33,34,35].