HAVCR1 and acute kidney injury: KIM-1 is a urinary injury marker that is highly upregulated in the proximal tubules in response to kidney injury.26 Increased levels of plasma and urine KIM-1 have been shown to be associated with AKI and CKD progression, and KIM-1 has been qualified by the US Food and Drug Administration as a biomarker of kidney injury for drug toxicity studies.26 KIM-1 is only produced in the kidney, so both higher plasma and urine levels likely reflect kidney tubule pathology, and it is unlikely that higher plasma levels of KIM-1 would reflect injury in nonkidney tissues.