CZ CELLxGENE from The Chan Zuckerberg Initiative, is a free-to-use online data portal collecting free and open-source tools for finding, querying, analysing, downloading and publishing single-cell data. As of April 2024, it includes some 85 million single cells 248 and 1,317 data sets covering 844 cell types. Most of the data represent single-cell RNA sequencing information from healthy human tissues, but non-human and cell-line data, as well as molecular-profiling data obtained using spatial transcriptomic methods, are also available.All of these data are stored in a common format, using a standard set of cell types and metadata (Perkel, JM, Nature 629, 248, 2may 2024) Registration not required.