CX3CR1 and Cognitive impairment: CX3CL1 and its receptor CX3CR1 are a representative pair of molecules, and a study has found that during the chronic period of 30 days post‐TBI, mice deficient in CX3CR1 that are subjected to CCI exhibit more obvious cognitive impairment and more neuronal death, which may be related to the polarization of M1 phenotype microglia [50].