GSTM1 and colorectal carcinoma: This concept is supported by the results of a study from The Netherlands in which the cumulative incidence of CRC after a negative result from an FIT and the sensitivity of the FIT for detection of CRC at low (≥15 μg Hb/g faeces) and high (≥47 μg Hb/g faeces) f-Hb thresholds were compared.19