IFT81 is a core component of the intraflagellar transport complex B (IFT-B) that plays essential roles in ciliogenesis and ciliary protein trafficking 1. Together with IFT74, IFT81 forms a tubulin-binding module that specifically mediates transport of tubulin within the cilium, with tubulin binding occurring through IFT81's calponin homology domain 1. The IFT74-IFT81 dimer functions as an unconventional GTPase-activating protein for RabL2, promoting its GTP hydrolysis during intraflagellar transport initiation 2. IFT81 also interacts with the IFT25-IFT27 dimer, and this interaction is crucial for proper BBSome-mediated export of ciliary membrane proteins including GPCRs 34. Mutations in IFT81 cause multiple ciliopathies with varying phenotypic presentations. Compound heterozygous mutations lead to short-rib thoracic dysplasia with polydactyly (SRTD19), often accompanied by features like situs inversus, micropenis, and rectal atresia 5. IFT81 variants can also cause nonsyndromic retinal degeneration through impaired photoreceptor cilium maintenance 6. Additionally, certain IFT81 variants that disrupt its interaction with IFT25-IFT27 can cause Bardet-Biedl syndrome-like ciliary defects, including accumulation of proteins within cilia and impaired GPCR export 7.