Lessons from postgenome-wide association studies: functional analysis of cancer predisposition loci

In the last few years, genome-wide association studies (GWASs) have identified hundreds of predisposition loci for several types of human cancers. Recent progress has been made in determining the underlying mechanisms through which different single-nucleotide polymorphisms (SNPs) affect predisposition to cancer. Although there has been much debate about the clinical utility of GWASs, less attention has been paid to how GWASs and post-GWASs functional analysis have contributed to understanding the aetiology of cancer. Most common variants associated with cancer risk are localized in nonprotein-coding regions highlighting transcriptional regulation as a common theme in the mechanism of cancer predisposition. Here, we outline strategies to functionally dissect predisposition loci and discuss their limitations as well as challenges for future studies.