We anticipate that our methods will be valuable to both individual labs but also larger consortia that have already invested in constructing and annotating comprehensive scRNA-seq references. For example, the Human Cell Atlas, Human Biomolecular Atlas Project, Tabula Sapiens70, and Human Cell Landscape71, all have released scRNA-seq references spanning hundreds of thousands of cells for multiple human tissues. Similar efforts are present in model organisms as well, including the Fly Cell Atlas72, and Plant Cell Atlas projects73. In each case, these efforts involve careful, collaborative, and expert-driven cell annotation alongside the curation of reference cell ontologies. While repeating this manual effort for each modality is infeasible, bridge integration enables the mapping of new modalities without having to modify the reference. As additional multi-omic datasets become available, we expect that tools such as Azimuth will begin to map additional modalities as well.
