Why is the number of compounds for a KEGG pathway different between the KEGG website and MetaboAnalyst?

In MetaboAnalyst, the KEGG pathways were obtained based on the KEGG REST APIs followed by manual curations. For some pathways, there may be a discrepancy in the number of compounds listed from KEGG directly compared to MetaboAnalyst (the compounds are primarily based on HMDB). This is because a KEGG pathway can contain compounds that have not been verified for that species or a generic compound, and there is no corresponding compound in HMDB. In most cases, these discrepancies should not affect data interpretation as we cannot measure those compounds anyway.