Centriolar protein required for centriole subdistal appendage assembly and microtubule anchoring in interphase cells (PubMed:28422092). Together with CCDC68, cooperate with subdistal appendage components ODF2, NIN and CEP170 for hierarchical subdistal appendage assembly (PubMed:28422092). Recruits NIN and CEP170 to centrosomes (PubMed:28422092). Also required for neurite growth (By similarity). Localizes CYTH2 to vesicles to allow its transport along neurites, and subsequent ARF6 activation and neurite growth (By similarity). Interacts with NIN and CEP170; leading to recruit them to centrosomes (By similarity). Interacts with CYTH2; this interaction is direct and stabilizes CCDC120, possibly by preventing ubiquitination (By similarity). Localizes to the subdistal appendages of mother centrioles and proximal ends of both centrioles in interphase cells (By similarity). Recruited to subdistal appendages by ODF2 (By similarity). In differentiating neuroblastoma cells, colocalizes with CYTH2 in both neurite shaft and growth cone areas (By similarity). Partially colocalizes with endosomes along neurites in differentiating neuroblastoma cells (By similarity). Ubiquitinated; interaction with CYTH2 may prevent ubiquitination.