Studies from several European countries, including Spain, Denmark, France, Sweden and Scotland, have reported high proportions of interval cancer in the programmes offering gFOBT as an initial screening test (range: 48–58%).27–31 Reported proportions were much lower in studies from the Netherlands (23%),32 Slovenia (14%),33 and Italy (10%),34 where FIT is used as primary CRC screening test and positivity thresholds are set at levels 10–20 μg Hb/g faeces. The gene discussed is GSTM1; the disease is colorectal carcinoma.