Somatic APC mutations are common events in colorectal adenocarcinomas, reported in up to 76% of the cases. Loss of normal APC function is known to be an early event in both familial and sporadic colon cancer pathogenesis, occurring at the pre-adenoma stage. APC mutations do not appear to significantly affect the prognosis of colorectal cancer patients. While there are a number of small molecule inhibitors in development that target the Wnt pathway, there is currently no matched targeted therapy available for colorectal cancer patients harboring an APC mutation. Germline defects in this gene cause familial adenomatous polyposis (FAP), an autosomal dominant pre-malignant disease that usually progresses to malignancy. Disease-associated mutations tend to be clustered in a small region designated the mutation cluster region (MCR) and result in a truncated protein product. Codon I1307 lies within a regulatory region of the APC protein mediated by ubiquitination. APC I1307K is associated with increased colorectal cancer risk by making the gene unstable and prone to acquire mutations during normal cell division. The germline APC I1307K gene mutation is most commonly found in people of Ashkenazi Jewish descent. Therefore, routine colorectal screening is very important in these individuals. Correlation with other clinical and lab findings is recommended.