GSTM1 and diabetes mellitus: We initially considered the following variables: preoperative and total inpatient days, mortality status, surgical procedure, graft conduit, diabetes status, HbA1c, BMI, blood glucose within 24 h of surgery, weight, smoker status, premorbid status, EuroSCORE-II, participation in an ongoing antibiotic prophylaxis study, shortage of chlorhexidine gluconate skin prep (CHG), operating room (OR) environmental issues, surgeon ID, Hb, WBC, blood transfusion, re-exploration, and duration of surgery.