Gratifyingly, known compounds that were unannotated by GNPS or by the in silico tools, were given a lower priority by MS2DECIDE than potential novel compounds. As in the case of pleiomutine (Fig. ), examination of some of those recommendations revealed that the exact masses and their structural annotations were already described in the species or the genus. Here, we can see that MS2DECIDE was able to complement the routine GNPS annotation by taking advantage of the convergent annotation of the in silico tools. One sees that MS2DECIDE helps the expert by providing information that is not given by any single tool.