Two expertly labeled odor datasets were combined to create IGD by Saini et al . These two datasets are Leffingwell and the training materials Firmenich supplied for the "Learning to Smell Challenge". Following preprocessing and merging, the final dataset had 7,374 molecules spread across 109 different odor classes, each with a different sample count (Fig. ). Supplementary File 1 contains the full list of all 7,374 odorant compounds.