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. {ECO:0000269|PubMed:18385425, ECO:0000269|PubMed:19944400, ECO:0000269|PubMed:19944405}. This is the function of DNAAF1 (dynein axonemal assembly factor 1, ENSG00000154099).