A germane question is whether a repeat FIT after a finding of an increase in f-Hb could help decide whether more traditional surveillance protocols with colonoscopy should be initiated, although there is little available evidence on the possible roles of repeat FIT in any clinical setting.19 It would also be of interest to investigate if serial f-Hb in patients with NAA and in AA, when f-Hb has fallen, could detect, at an early stage, development of neoplasia; early detection of lesions is another ideal attribute of a tumour marker. Here, GSTM1 is linked to neoplasm.