Small GTPase-like component of the intraflagellar transport (IFT) complex B that promotes the exit of the BBSome complex from cilia via its interaction with ARL6 (PubMed:25443296). Not involved in entry of the BBSome complex into cilium. Prevents aggregation of GTP-free ARL6 (PubMed:25443296). Required for hedgehog signaling. Forms a subcomplex within the IFT complex B with IFT25. Its role in intraflagellar transport is mainly seen in tissues rich in ciliated cells such as kidney and testis. Essential for male fertility, spermiogenesis and sperm flagella formation. Plays a role in the early development of the kidney. May be involved in the regulation of ureteric bud initiation (By similarity). Component of the IFT complex B, at least composed of IFT20, IFT25/HSPB11, IFT27, IFT52, IFT57, IFT74, IFT81, IFT88 and TRAF3IP1 (PubMed:25443296). Interacts with IFT25/HSPB11 (By similarity). Interacts with TTC30B (By similarity). Interacts with RABL2/RABL2A; binding is equal in the presence of GTP or GDP (By similarity). Interacts with ARL6; recognizes and binds with the GTP-free form of ARL6 (PubMed:25443296). Localizes to the sperm flagellum. The disease is caused by variants affecting the gene represented in this entry. Belongs to the small GTPase superfamily. Rab family.