Although several molecules such as NGAL, KIM-1, IL-18, L-FABP, IL-6, α/π GST, NAG, IGFBP7, and TIMP-2 have been reported to have a role in the diagnosis of AKI, none has been put into clinical use due to their specific deficiencies and problems particularly concerning their measurement method.1,3,8 Therefore, there is an ongoing search for a sensitive, specific, reliable, easy-to-measure, and cost-effective marker for the early diagnosis of AKI. Here, TIMP2 is linked to acute kidney injury.