STAT3 and acute kidney injury: Indeed, as we have shown previously, IL-6 trans-signaling by the recombinant IL-6/sIL-6R fusion protein, Hyper-IL-6 (HIL-6) (18) can strongly upregulate STAT3 phosphorylation in the kidney and largely prevent ROS-mediated acute kidney injury (AKI) (10, 19).