Required for posterior migration of cells and axon growth cones during nervous system assembly. Required for posterior migration of the axon growth cone and the ALM cell body (PubMed:9581759, PubMed:17237778). May enhance posterior migration by regulating the subcellular location or stability of guidance cue receptors such as sax-3 and unc-40, promoting their localization to the cell surface (PubMed:17237778). In PLM neuron, regulates innexin unc-9 gap junction turnover by suppressing unc-9 transport out of the gap junctions (PubMed:27015090). Specifically required for CAN cell migration. Interacts with unc-51 and unc-73 (PubMed:15539493, PubMed:17237778). Isoform a: Interacts with unc-33 isoform c (PubMed:27015090). Isoform a is expressed in the AVKR neuron. Isoform b is expressed in the CAN cells and in the body wall muscle. Also expressed in the motor neurons of the ventral nerve cord and additional neurons in the pharynx and head. Phosphorylated by unc-51. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Kinesin family. KIF26 subfamily.