Iron therapy reduced α-SMA expression not only in whole kidney tissue but also specifically in kidney mononuclear cells (Supplemental Figure 7A) and appeared to decrease coexpression of α-SMA and F4/80 in kidney tissue (Supplemental Figure 7B), suggesting that iron dextran administration reduced kidney macrophage-to-myofibroblast transition in CKD. Here, ACTA1 is linked to chronic kidney disease.