MAPK3 and renal fibrosis: It is well known that the TGF-β1/Smad3 pathway is key to the development of EMT and renal fibrosis (Inazaki et al., 2004), and other signaling pathways such as STAT3 and ERK1/2 also contribute to these processes (Matsui and Meldrum, 2012; Pang et al., 2010; Bienaime et al., 2016; Andrikopoulos et al., 2019; J.; Chen et al., 2012; Rhyu et al., 2005).