Thus, we could propose that fibrillin-1 mutation–facilitated TGF-β signaling promoted MCP-1 production in ECs and VSMCs and subsequently recruited circulating CCR2-expressed Ly6Chi monocytes, which differentiated into macrophages, thereby favoring the accumulation of intimal CX3CR1+ macrophages during the pathogenesis of TAAs in MFS. Here, CX3CR1 is linked to Marfan syndrome.