It has been stated that further research is warranted to better define potential applications.8 In consequence, the aim of this study was to determine, for the first time, using a quantitative FIT at very low f-Hb, as defined by the analytical detectability characteristics,10 (a) whether f-Hb had the characteristics of an ideal tumour marker in this clinical setting and (b) whether f-Hb changed following polypectomy in patients at increased risk of CRC and engaged in a surveillance programme. This evidence concerns the gene GSTM1 and colorectal carcinoma.