Probable planar cell polarity effector involved in cilium biogenesis. 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. May regulate protein and membrane transport to the cilium. May control the organization of the apical actin cytoskeleton, which is essential for the normal orientation of elongating ciliary microtubules. Interacts with rsg1 (PubMed:19767740). Interacts with intu and wdpcp; fuz, intu and wdpcp probably form the core CPLANE (ciliogenesis and planar polarity effectors) complex (By similarity). Expressed in the neural tube closure, with strongest expression in the floorplate. Expressed in ciliated epidermal cells. Knockdown of fy disrupted Hedgehog signaling and caused defects in neural tube closure, including exencephaly, spina bifida, and holoprosencephaly-like features. Belongs to the fuzzy family.