In contrast, in colorectal cancers, the adenomatous polyposis coli (APC) tumor suppressor gene can be disrupted by infrequent insertion of LINE-1 elements to drive tumorigenesis in 1-2% of cases53–55, but normal colorectal stem cells appear to be a privileged environment tolerating somatic LINE-1 retrotransposition56. This evidence concerns the gene APC and colorectal cancer.