Studies on the relationship between microglial activation, toll-like receptor 4 (TLR4), and novel tyrosine kinase Lck/Yes (LYN) signaling in a mouse model of AD show a correlation between microglial TLR4 and LYN colocalization and AD pathogenesis, greater in females than in males of 5XFAD mice [138]. Here, TLR4 is linked to Alzheimer disease.