APC gene
From Biolecture.org
Adenomatous polyposis coli (APC) also known as deleted in polyposis 2.5 (DP2.5) is a protein that in humans is encoded by the APC gene.The APC protein is a negative regulator that controls beta-catenin concentrations and interacts with E-cadherin, which are involved in cell adhesion. Mutations in theAPC gene may result in colorectal cancer. (By wikipedia)
APC gene has long exon15 and most important region is located in exon15.