Notably, we identified 3 genes encoding EGFR ligands markedly upregulated in our AKI-to-CKD transition model: immediate early transient expression of the heparin-binding epidermal growth factor, Hbegf, and more persistent elevation of Areg (amphiregulin) and Nrg1 (neuregulin 1). This evidence concerns the gene NRG1 and acute kidney injury.