Plays an important role in ciliogenesis. Required for apical targeting/anchoring of centrioles at the plasma membrane. Localized to basal bodies in multiciliated cells (PubMed:19656802). Morpholino knockdown results in a specific loss of cilia, with no effect on the number of cells with multiple basal bodies or the number of basal bodies per cell. Belongs to the HYLS1 family.