A metabolite set can be any externally defined groups of metabolites that has something in common. For example,
- Metabolites that are involved in the same pathways (SMPDB, KEGG, Biocarta);
- Metabolites that are changed significantly under the same conditions;
- Metabolites that are associated with the genomic variations (i.e. single nucleotide polymorphism or SNPs);
- Metabolites that are located in the same cellular compartments;
- Other published metabolite signatures, ontology terms, etc.
Please note that you can define your own metabolite set for functional enrichment analysis using MSEA.