Loss of both alleles of the tumour suppressor gene Adenomatous Polyposis Coli (APC) is believed to occur prior to development of the benign precursor lesion of colorectal cancer (CRC), the colorectal adenoma (or polyp), in the majority of cases of sporadic colorectal carcinogenesis (Wong and Pignatelli, 2002). The gene discussed is APC; the disease is colorectal carcinoma.