MAPK9 and renal fibrosis: In renal fibrosis, TGF- β1 binds to a trans-membrane TBRII receptor and initiates several intracellular signalling cascades, including the small mothers against decapentaplegic (SMADs) and mitogen activated protein kinases (MAPK), such as extracellular regulated kinase (ERK), p38 and Jun Kinase [22].