Cilium-specific protein required for the stability of the ciliary architecture. Plays a role in cytoplasmic preassembly of dynein arms. Involved in regulation of microtubule-based cilia and actin-based brush border microvilli. In HEK293T cells, it is diffusely cytoplasmic and concentrates at the mitotic spindle poles, while in MDCK cells, it localizes in the cilium. In vivo, this protein is probably restricted to the cilium. Mainly expressed in trachea and testis. The disease is caused by variants affecting the gene represented in this entry. Belongs to the DNAAF1 family.