CCL4 and major depressive disorder: Here, we planned to measure serum MIP-1β and MCP-2 levels in MDD patients compared to HCs and evaluate the strength of distinction ability of these chemokines as a diagnostic tool Also, we intended to compare the level of alterations with the severity of depressive symptoms to shed light on the underlying inflammatory processes that contribute to MDD and to pave the way for the development of diagnostic and therapeutic approaches that target neuroinflammatory pathways in MDD.