CCL21 and atherosclerosis: Whereas chemokines (family of small cytokines) involved in atherosclerosis advancements are CC-chemokine ligand (CCL) 2, CCL3, CX3C-chemokine ligand (CXCL) 4, CCL5, CXCL1, CX3CL1, CCL17, CXCL8, CXCL10, CCL20, CCL19, CCL21, and macrophage migration-inhibitory factor [10].