Location of Tumors Detected by SEPT9 Blood-Based Test. The diagram illustrates the locations of the primary tumors that were detected using the blood-based methylated SEPT9 DNA test. Note that CRCs were identified throughout the large intestine, including proximal regions such as the cecum. Three of the fifty blood specimens did not have tumor locations recorded, therefore these specimens are not represented by this figure. CRC, colorectal cancer.