Most existing models predict odor perception at just one concentration. Yet, some odorants dramatically shift in quality as concentration changes—such as grapefruit mercaptan, pleasantly fruity at low concentrations but distinctly sulfurous at high levels.

Last year, we ran the second DREAM Olfaction Prediction Challenge www.synapse.org/Synapse:syn5... . This time focusing on predicting the similarity of mixture pairs.

Ten years ago the first DREAM Olfaction Prediction Challenge launched to predict the smell of a molecule from its structure. This led to a publication establishing benchmarks doi.org/10.1126/scie... , and then a subsequent surge in predictive modeling.