Observations in rodents showed that the proximal tubule has IGF-1Rs and is responsive to IGF-1, and that renal IGF synthesis, including the collecting duct, is transiently increased in animal models of postischemic AKI, thereby providing the rationale for the use of rhGH or rhIGF-1 in AKI in order to improve kidney regeneration [3]. Here, IGF1 is linked to acute kidney injury.