Required for normal spindle assembly. Plays a key role in mother-centriole-dependent centriole duplication; the function seems also to involve CEP152, CDK5RAP2 and WDR62 through a stepwise assembled complex at the centrosome that recruits CDK2 required for centriole duplication. Reported to be required for centrosomal recruitment of CEP152; however, this function has been questioned (PubMed:21983783, PubMed:26297806). Also recruits CDK1 to centrosomes (PubMed:21406398). Plays a role in DNA damage response. Following DNA damage, such as double-strand breaks (DSBs), is removed from centrosomes; this leads to the inactivation of spindle assembly and delay in mitotic progression (PubMed:21406398). Interacts with CEP152 and CDK1; these interactions recruit both ligands to centrosomes (PubMed:21406398). Interacts with CDK2, CDK5RAP2, WDR62, CEP90, KIAA0753/moonraker and CCDC14. CEP63, CDK5RAP2, CEP152, WDR62 are proposed to form a stepwise assembled complex at the centrosome forming a ring near parental centrioles (PubMed:21406398, PubMed:26297806). Interacts with CCDC57; the interaction is required for their location to proximal end of centrioles (PubMed:32402286). Colocalizes with CDK5RAP2, CEP152 and WDR62 in a discrete ring around the proximal end of the parental centriole. At this site, a cohesive structure is predicted to engage parental centrioles and procentrioles. The disease is caused by variants affecting the gene represented in this entry. CEP63 and DEUP1 paralogs are both involved in centriole amplification: while CEP63 mediates mother-centriole-dependent centriole duplication, DEUP1 mediates de novo centriole amplification in multiciliated cells. Belongs to the CEP63 family.