Department of Epidemiology, University Hospitals of Cleveland/Case Western Reserve University and Howard Hughes Medical Institute, and Cleveland, Ohio, USA. ddaley@mrl.ubc.ca
Our analysis definitely excludes the possibility of the TGFBR1*6A allele increasing the risk of colorectal neoplasia in our sample population. A recent study validating linkage of colorectal cancer to chromosome 9q also excluded the TGFBR1*6A allele as a disease-causing variant in that sample. We conclude that there remains an unidentified susceptibility locus in the region 9q22.2-31.2.