CXCR2 and neoplasm: Interestingly, these pathways are utilized by a series of chemokines and their receptors, such as CCL20/CCR6 [91], CCL25/CCR9 [92], CXCL1/CXCR2 [93], CXCL8/CXCR1-2 [94], CXCL12/CXCR4 [95], and CX3CL1/CX3CR1 [96], to inhibit apoptosis and promote tumor cell growth and proliferation.