SCGSv2 is a manually curated list of known ciliary components compiled with expert review, with entries grouped into first-order and second-order cilia genes, elaborating a concept first put forward by Reiter and Leroux (2017, Nat Rev Mol Cell Biol 18, 533-547). A comparison of SCGSv1 and SCGSv2 is provided to give an overview of the advances made in the cilia field since 2013.
