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. Localizes CYTH2 to vesicles to allow its transport along neurites, and subsequent ARF6 activation and neurite growth. Interacts with NIN and CEP170; leading to recruit them to centrosomes (PubMed:28422092). Directly interacts with CYTH2; this interaction stabilizes CCDC120, possibly by preventing ubiquitination. Localizes to the subdistal appendages of mother centrioles and proximal ends of both centrioles in interphase cells (PubMed:28422092). Recruited to subdistal appendages by ODF2 (PubMed:28422092). In differentiating neuroblastoma cells, colocalizes with CYTH2 in both neurite shaft and growth cone areas (PubMed:25326380). Partially colocalizes with endosomes along neurites in differentiating neuroblastoma cells (PubMed:25326380). Ubiquitinated; interaction with CYTH2 may prevent ubiquitination.