Given that disturbances in iron metabolism are associated with inflammation and that oxidative stress is involved in AKI pathogenesis, Vilander and colleagues performed the targeted genotyping of 300 patients with severe AKI (KDIGO 2 or 3) and 353 controls without AKI (KDIGO 0) for the guanine-thymine (GTn) repeat in the promoter region of the heme oxygenase-1 gene (HMOX1) [19]. The gene discussed is HMOX1; the disease is acute kidney injury.