Univariate logistic regression analysis (Table 2) showed 11 potential risk factors associated with the occurrence of AL: age, anastomotic location, and some preoperative laboratory results, including RBC, Hb, ALB, LMR and some postoperative laboratory results, including WBC count, RBC count, NLR, LMR, and CRP/ALB. The gene discussed is GSTM1; the disease is axial length measurement.