In parallel, we examined the gene and protein expression of the CX3CL1–CX3CR1 and CD200–CD200R ligand–receptor axes, as well as microglial pro- and anti-inflammatory phenotypes and the possible microglia priming properties in the context of the “two-hit” hypothesis of schizophrenia. The gene discussed is CX3CL1; the disease is schizophrenia.