The serum level of WBC, platelet and albumin were similar between groups, while the mean Hb (hemoglobin) and pre-albumin levels in SSI group were lower than normal range, and was significantly lower than that in non-SSI group (p = 0.02), indicating a relatively high prevalence of anemia and malnutrition in patients of SSI group. The gene discussed is GSTM1; the disease is anemia (phenotype).