For the complication score, we assigned each patient 1 point for each of the factors that have been proven to be significantly associated with the development of postoperative complications: Hb<11.05 g/dL; preoperative serum albumin<3.55 g/dL; tumor localization: right-sided colon; EC: NO; use of opioids: yes; NPO (nothing by mouth) duration>2.5 days. The gene discussed is GSTM1; the disease is neoplasm.