Although the variation of cancer incidence is likely to be the result of several factors, there is a large body of literature that strongly implicates a genetic etiology.With strong evidence for a genetic component, genome-wide association studies (GWAS) have successfully identified numerous single nucleotide polymorphisms (SNPs) associated with an increased cancer risk.However, there has been a missing link between the GWAS findings and underlying cancer biology.So far, the mechanism of action for the majority of these risk-SNPs has not been elucidated yet.The fact that many of these risk-SNPs have been found in non-coding regions of the genome, some residing at long distances from any nearby gene, suggests that many, if not most, of these risk-SNPs (or their closely linked causal-SNPs) are located in regulatory regions.Here, I will present our recent study using network-based systems genetics approach for uncovering the missing links between GWAS findings and underlying biology in prostate cancer.