Nomenclature	CXCR1	CXCR2	CXCR3
HGNC, UniProt	CXCR1, P25024	CXCR2, P25025	CXCR3, P49682
Endogenous agonists	CXCL8 (CXCL8, P10145) (pK i 8.8–9.5) [142, 675, 1068, 2032, 2049], CXCL6 (CXCL6, P80162) (pK i 7) [2053]	CXCL1 (CXCL1, P09341) (Selective) (pK i 8.4–9.7) [675, 1068, 2049], CXCL8 (CXCL8, P10145) (pK i 8.8–9.5) [142, 675, 1068, 2032, 2049], CXCL7 (PPBP, P02775) (Selective) (pIC50 6.3–9.3) [16], CXCL3 (CXCL3, P19876) (Selective) (pIC50 7.8–9.2) [16], CXCL2 (CXCL2, P19875) (Selective) (pIC50 7–9.1) [16], CXCL5 (CXCL5, P42830) (Selective) (pIC50 6.9–9) [16], CXCL6 (CXCL6, P80162) (pK d 7) [2053]	CXCL11 (CXCL11, O14625) (Selective) (pK i 10.4–10.5) [734], CXCL10 (CXCL10, P02778) (Selective) (pK i 7.8–9.8) [734, 2006], CXCL9 (CXCL9, Q07325) (Selective) (pK i 7.3–8.3) [734, 2006]
Agonists	vCXCL1 (pIC50 7.4) [1158], HIV‐1 matrix protein p17 (pK d 5.7) [602]	vCXCL1 (pIC50 8.2) [1158], HIV‐1 matrix protein p17 (pK d 6.9) [602]	–
Selective agonists	–	–	–
Endogenous antagonists	–	–	CCL11 (CCL11, P51671) (Selective) (pK i 7.2) [2006], CCL7 (CCL7, P80098) (Selective) (pK i 6.6) [2006]
Antagonists	–	–	–
Selective antagonists	–	navarixin (pIC50 10.3) [78, 456], danirixin (pIC50 7.9) [1285], SB 225002 (pIC50 7.7) [2016], elubirixin (pIC50 7.7) [78], SX‐517 (pIC50 7.2) [1172]	–
Allosteric modulators	reparixin (Negative) (pIC50 9) [142]	reparixin (Negative) (pIC50 6.4) [142]	–
Labelled ligands	[125I]CXCL8 (human) (Agonist) (pK d 8.9–9.6) [675, 1584]	[125I]CXCL8 (human) (Agonist) (pK d 9–9.4) [675, 1584], [125I]CXCL1 (human) (Agonist), [125I]CXCL5 (human) (Agonist), [125I]CXCL7 (human) (Agonist)	[125I]CXCL10 (human) (Agonist), [125I]CXCL11 (human) (Agonist)
Comments	Reports on the expression of native CXCR1 by mouse leukocytes are not conclusive. There are reports on the existence of mouse Cxcr1 and on Cxcr1 knockout mice, but the distinct function of the gene and of its knockout phenotype are unclear [118, 351, 1297, 1628, 1794].	–	–