Component of the intraflagellar transport (IFT) complex B required for transport of proteins in the motile cilium (PubMed:28479320). May be required for ciliary entrance and transport of specific ciliary cargo proteins such as che-3 which are related to motility (PubMed:28479320). Regulates specific signaling activities in the cilia, such as the daf-2/insulin receptor-like transduction pathway (PubMed:16968739). Component of the IFT complex B composed of at least che-2, che-13, dyf-1, dyf-3, dyf-6, dyf-11, dyf-13, ift-20, ift-74, ift-81, ifta-2, osm-1, osm-5 and osm-6. Moves along the axoneme. Ciliated sensory neurons. Worms have an extended lifespan phenotype and are defective in dauer formation. Belongs to the small GTPase superfamily. Rab family. In contrast to other members of the family, does not contain a prenylation domain.