It is instructive to note that for the 4,366 compounds in Group-I of Table 1 , there are still 1,229 compounds that can not be processed by the current method due to lack of the interaction information with other compounds within the dataset. It is expected that the problem can be solved by collecting as much chemical-chemical interaction information as possible from STITCH, which is a large-scale and well-maintained resource in chemical biology, including the interactions information for over 2.5 million proteins and over 74,000 small molecules in 630 organisms. With the continuous increase of the interactions information, the performance of our method will be further improved.