MMP9 and renal fibrosis: Huang et al. (2014a) further demonstrated that blockade of KCa3.1 attenuated renal fibrosis in a diabetic mouse model, and the downregulation of collagen synthesis, α-smooth muscle actin as well as the reduction in fibroblast activation supported this result. Importantly, in human renal interstitial fibroblasts, TRAM34 inhibited cell activation induced by TGF-β1 and also reduced the expression of fibrosis-related genes matrix metalloproteinase-2 (MMP2) and MMP9 (Huang et al., 2014a), suggesting a prominent role of targeting KCa3.1 in reversing renal fibroblast activation.