Plays a key role in ciliogenesis and embryonic development. Regulator of cilia formation by controlling the organization of the apical actin cytoskeleton and the positioning of the basal bodies at the apical cell surface, which in turn is essential for the normal orientation of elongating ciliary microtubules. Plays a key role in definition of cell polarity via its role in ciliogenesis but not via conversion extension. Has an indirect effect on hedgehog signaling (By similarity). Proposed to function as core component of the CPLANE (ciliogenesis and planar polarity effectors) complex involved in the recruitment of peripheral IFT-A proteins to basal bodies (PubMed:27158779). Required for recruitment of CPLANE2 to the mother centriole (By similarity). Binds phosphatidylinositol 3-phosphate with highest affinity, followed by phosphatidylinositol 4-phosphate and phosphatidylinositol 5-phosphate (By similarity). {ECO:0000250|UniProtKB:Q059U7, ECO:0000250|UniProtKB:Q2I0E5, ECO:0000305|PubMed:27158779}. This is the function of INTU (inturned planar cell polarity protein, Ensembl gene identifier ENSG00000164066).