Organized CRC screeningprograms in Europe commonly use fecal-based tests such as the guaiac fecal occultblood tests (gFOBT) or fecal immunochemical testing (FIT).6 As of 2015, 20 of 28 EU member states were in various stages of implementingpopulation-based CRC screening (Appendix Table 1).7 Recent reports show that more than half of these use FIT.8 Although the most common screening interval was every 2 year, there aresignificant differences in FIT thresholds in use, ranging from 6 to 180 μg ofhaemoglobin per gram of feces (μg Hb/g). Here, GSTM1 is linked to colorectal carcinoma.