GSTM1 and colorectal carcinoma: The median f-Hb concentration for all screen-detected CRC women was 408 μg Hb/g faeces compared to 473 μg Hb/g faeces for men (p = 0.004) and 50.6% of the results were >400 μg Hb/g faeces in women whereas in men this was 57.8%.