Part of the goal of our current work on CIDO, VIDO, and IDO-COVID-19 is to provide a model according to which other IDO extension ontologies can be brought into tighter coordination with the Core, as well as an easy-to-follow recipe for building new pathogen- specific ontologies so that infectious disease researchers are given fewer opportunities to generate inoperable ontologies. This evidence concerns the gene IDO1 and COVID-19.