CEP164 was initially identified as a centrosomal protein, but other studies have indicated that it also plays a role in the formation of primary cilia, the microtubule-based sensory antennae projecting from the surface of many eukaryotic cells as well as in DNA damage response acting as a mediator protein. CEP164 interacts with both ATR and ATM, proteins that trigger a number of cellular responses including the initiation of DNA damaged-induced cell cycle checkpoints. It is phosphorylated upon replication stress, ultraviolet (UV) radiation, and ionizing radiation; silencing of CEP164 significantly reduces the DNA damage-induced phosphorylation of several proteins in the DNA damage-activated signaling cascade and compromises cell survival after UV damage. At least two isoforms of CEP164 are known to exist.
