GSTM1 and malignant colon neoplasm: In a study conducted on men over 60 years of age in the UK, in the event of Hb < 11 g/dl and iron deficiency anemia, colon cancer incidence rate was 13.3% while in women of the same age group with Hb < 10 g/dl, this rate was reported to be 7.7% [23].