“…Another important subfamily of class A GPCRs with a number of key physiologic roles are the Chemokine receptors [17]. So far (till 2020) only 5 different chemokine receptor complexes have had their crystal structure solved by researchers and they are CXCR4 [18] (PDB IDs: 3ODU, 3OE0, 3OE6, 3OE8, 3OE9, and 4RWS [18,19]), CCR5 [20] (PDB IDs: 4MBS, 5UIW, 6AKX, and 6AKY [21][22][23]), US28 [24] (PDB IDs: 4XT1, 4XT3, 5WB1, and 5WB2 [24,25]), CCR2 [26] (PDB IDs: 5T1A, 6GPS, and 6GPX [26,27]) and CCR9 [28] (PDB ID: 5LWE [28]).…”