It is well known that excessive ROS directly damages DNA, proteins and lipids and indirectly activates a variety of stress‐sensitive intracellular signalling pathways, such as p38MAPK and JNK, thus impairing the insulin pathway.26, 42, 43 In our study, NEFA treatment induced the overactivation of JNK and p38MAPK and inhibition of AKT in cow hepatocytes and HepG2 cells, and inhibition of JNK and p38MAPK could improve NEFA‐induced insulin resistance. Here, INS is linked to Insulin resistance.