As indicated by the above discussion and analysis, the results derived from the 1 st and 2 nd order predictions should be considered as the candidates for the metabolic pathway classes with which the query compound may be involved. In view of this, biochemical experiments should be conducted by mainly focusing on the targets predicted by the 1 st and 2 nd order predictions. The results obtained by the last five order predictions can be ignored due to their very low likelihood (,2%). Consequently, the current prediction method can provide useful clues for further validation by experiments and expedite the research progress by prioritizing the targets concerned.