Because the p38α MAPK are activated by MKK3 and MKK6 and JNK are directly activated by MKK4 and MKK7, we thus knockdown the MKK3/6 and MKK4/7 respectively to investigate possible mechanisms of p38α MAPK and JNK involved in the liver steatosis. This evidence concerns the gene MAP2K4 and fatty liver disease.