SMAD2 and renal fibrosis: Our results showing that the pharmacological reduction in HA by PEGPH20 or the genetic deletion of CD44 ameliorated renal fibrosis (i.e., decreased HA and collagen deposition) and reduced fibroblast differentiation (i.e., decreased α-SMA and TGF-β1/Smad2/3 signalling) in HF-fed mice were consistent with these previous findings [34].