Plays an important role in primary cilium assembly, maintenance, and length regulation. Interacts with centriole inner scaffold proteins to promote proper centriole size and integrity and assembly of functional cilia. Required for the recruitment of both the inner scaffold protein POC1B and the distal SFI1/CETN2 complex to centrioles. . This is the function of CCDC15 (coiled-coil domain containing 15, Ensembl gene identifier ENSG00000149548).