At low ("rule-out") faecal haemoglobin (f-Hb) thresholds, the sensitivity and specificity for CRC were 93.8% (CI 79.2-99.2) and 75.9% (CI 73.1-78.5) for f-Hb ≥4 μg/g and 90.6% (CI 75.0-98.0) and 83.1% (CI 80.6-85.4) for f-Hb ≥10 μg/g. This evidence concerns the gene GSTM1 and colorectal carcinoma.