SMAD3 and kidney disorder: Several studies have investigated the role of Smad2 and Smad3 in the pathogenesis of different renal diseases in vivo (Fujimoto et al. 2003; Inazaki et al. 2004; Meng et al. 2010; Nath et al. 2011; Sato et al. 2003; Wang et al. 2007; Warner et al. 2012; Zhou et al. 2010).