The number of patients required to undergo colonoscopy to detect 1 CRC also known as the number needed to scope was inversely proportional to the FIT cut-off values of ≥10, >100 and >200 μg Hb/g; this was 10.8, 6.03 and 5.20, respectively. The gene discussed is GSTM1; the disease is colorectal carcinoma.