A recent study comparing the detection rate of KRAS (KRAS proto-oncogene, GTPase) mutations not only in blood and tumor tissue but also in stool, found a higher overall agreement between stool versus tissue (84.9%) than between blood versus tissue (77.4%) in CRC patients.9 Another study comparing the detection of known mutations in blood and stool of CRC patients concluded that stool may even provide a better source for mutation testing than plasma.10 Here, KRAS is linked to colorectal carcinoma.