For example, CCL2 attracts CCR2+ NK cells to the liver during murine cytomegalovirus (MCMV) infection (Hokeness et al., 2005), CX3CL1 recruit CX3CR1+ NK cells into the CNS of experimental autoimmune encephalomyelitis (EAE) mice (Huang et al., 2006), CXCL10 attracts CXCR3+ NK cells accumulate into the ischemic brain tissues (Zhang et al., 2014), CCL3/CCL4/CCL5 attracts CCR5+ NK cells to the synovial fluid of rheumatoid arthritis (RA) patients (Parolini et al., 2007). Here, CX3CR1 is linked to rheumatoid arthritis.