About Selecting Target of Enrichment
ChEBI structure classification: The structure classification describes a molecular entity based on its composition and/or the connectivity between its constituent atoms.
ChEBI role classification: The role classification describes the role of a molecular entity within a biological context and/or its intended use by humans.
ChEBI structure and role classification: The structure and role classification is the union
of both classifications. Note that the structure classification is significantly larger than the role
classification.
Your selected target of enrichment has to include your study set for correct calculations.