The iOdorTool module has two functions related to odourant information. The PheroInfo tool provides information on the 2077 pheromone molecules collated in iORbase, from which 3D structures after energy minimization can be displayed or downloaded. The OdorSeek tool can identify the structural similarity between user-queried odourants and pheromones in iORbase, and the most similar pheromones and their positions in physicochemical space are also shown. Moreover, visitors can easily jump to the iInteraction module to obtain information for the potential interacting iORs with their query odourants based on the structural information of similar pheromones. The suggested iOR-ligand interactions of most similar odourant molecules with query odourants are important for finding the potential interacting iORs of user-submitted odourants, because similar VOCs are often bound by the same olfactory receptors. Please chose your interested pheromone or input query odorant in PheroInfo or OdorSeek tools, respectively.