IRS1 and Insulin resistance: A study has shown that non-IRS-1-dependent tyrosine kinases receptors are also defective in AKT signalling when the cells become insulin resistant [35] indicating that while oxidative stress and increase of insulin resistance via IRS-1 Ser phosphorylation can happen in obese and diabetic states, it is possible that ROS and downstream IRS-1 serine phosphorylation will promote insulin resistance.