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 (PubMed:20067783, PubMed:21761479). 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 (By similarity). Interacts with CPLANE1. Interacts with FUZ and WDPCP; FUZ, INTU and WDPCP probably form the core CPLANE (ciliogenesis and planar polarity effectors) complex. Enriched at the apical surface in ciliated cells. Widely expressed in E8.5 and E9.5 wild type embryos. Present in various adult organs (at protein level). Embryos die at midgestation. Embryos exhibit multiple defects including neural tube closure defects, abnormal dorsal/ventral patterning of the central nervous system and abnormal anterior-posterior patterning of the limbs resulting in severe polydactyly. Fewer and shorter cilia are present in mutant embryos. In mice lacking both Intu and Fuz, the lack of convergent extension and more severe patterning defects in Intu and Fuz mutants does not result from a functional redundancy between these proteins. Belongs to the inturned family.