The following variables were screened for association with the development of postoperative AKI: age, gender, additive Euroscore, serum creatinine, duration of CPB, duration of surgery, type of surgery, total circulatory arrest, preoperative hemoglobin level, preoperative oxygen supplemented cerebral oxygen saturation (ScO2), diabetes mellitus, hemofiltration during CPB, plasma GDF-15, high sensitivity troponin T (hsTNT), and N-terminal prohormone of B-type natriuretic peptide (NTproBNP). The gene discussed is NPPB; the disease is acute kidney injury.