Figure 1.

Schematic illustration of the factors that can affect metabolic pathway analysis of metabolomics data, at different stages of the study. Inputs: affected by the organism and pathway database chosen; affected by the significance threshold used to choose the number of metabolite hits. Pathway analysis: the use of a background set (reference metabolome) is particularly important. Outputs: have the P values for the pathways been corrected for multiple testing (based on the total number of pathways in the database)?