Several patient and procedure-related risk factors have been linked with the development of AKI after abdominal surgery, namely older age, male gender, hypertension, metastatic cancer, hypoalbuminemia, diabetes mellitus, CKD, use of angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers, use of intravenous contrast, use of diuretics and vasopressors, more invasive surgeries, episodes of intraoperative hemodynamic instability, need for intra-operative blood transfusions, and large colloid infusion during surgery [23,47,48]. Here, ACE is linked to metastatic malignant neoplasm.