However, several countries, including the UK and The Netherlands, where again it has been shown that the proportion of IC in FIT-based screening appears to be lower than that with gFOBT,18 have CRC population screening programmes using FIT at f-Hb thresholds higher than ≥20 μg Hb/g faeces to cope with colonoscopy capacity. Here, GSTM1 is linked to colorectal carcinoma.