For classification purposes, first-order ciliopathies are those diseases which occur due to a mutation in genes required for the proper assembly, maintenance, or function of the cilia or the related centriole; second-order ciliopathies occur due to dysregulation of further upstream factors, such as the nuclear transcription factors Atf3, Tsc22d4, and Cbx5 [26,27]. This evidence concerns the gene ATF3 and ciliopathy.