Immunohistochemical score of 4-HNE, NGAL, and HO-1 expression, as a semi quantitative analysis, was significantly higher in the AKI group for all observed parameters, compared to SHAM control (4-HNE, p < 0.001; NGAL, p < 0.001; HO-1, p < 0.001). The gene discussed is HMOX1; the disease is acute kidney injury.