As a part of the multicenter FINNAKI cohort study, we performed a pilot study among critically ill patients who developed AKI matched to critically ill patients without AKI and explored the urine and plasma levels of cytokeratin-18 neoepitope M30 (CK-18 M30), cell-free DNA, and HSP70 at ICU admission and 24h thereafter, before the clinical diagnosis of AKI and according to the presence of septic AKI. The gene discussed is KRT18; the disease is acute kidney injury.