“An important attribute of metabolites is their close relationship to both the biological states of interest (i.e. disease status) and relevant genomic, transcriptomic, and proteomic variants causally related to the disease state. As such, metabo-profiles can be viewed as an intermediate measure that links pre-disposing genes and environmental exposures to a resulting disease state. Causal metabolites also typically have a stronger relationship (i.e. larger effect size) to the underlying genetics and the disease phenotype. Thus, the integration of metabolomic data into systems biology approaches may provide a missing link between genes and disease states.”