New insights into the aetiology of colorectal cancer from genome-wide association studies.

Genome-wide association studies have recently identified ten common genetic variants associated with colorectal cancer susceptibility, several suggesting the involvement of components of the transforming growth factor beta (TGFbeta) superfamily signalling pathway. To date, no causal sequence variants have been identified, and risk seems to be mediated through effects on gene regulation. Several markers are located close to poorly characterized genes or in gene deserts, raising challenges for elucidating mechanisms of susceptibility. Disease-associated common genetic variation offers the potential to refine risk stratification within populations and enable more targeted disease prevention strategies.