MAPK8 and fatty liver disease: The activated TAK1 further lead to an activation of downstream MKK–JNK–IRS1307 and IKKβ–NF-κB signalling, and an inhibition of AKT–GSK3β/FOXO1 phosphorylation cascades, facilitating the insulin resistance, inflammatory response and glucose metabolic disorder in the liver, thereby exacerbating fatty acid accumulation and the resultant hepatic steatosis (Fig. 10).