Here, we determined the serum and hepatic content of miR-21 in patients with liver cirrhosis and rats with dimethylnitrosamine-induced hepatic cirrhosis and examined the effects of miR-21 on SPRY2 and HNF4α in modulating ERK1 signaling in hepatic stellate cells (HSCs) and epithelial-mesenchymal transition (EMT) of hepatocytes. Here, MAPK3 is linked to Cirrhosis.