The kinesin superfamily of proteins consists of over forty KIF motor proteins that function in intracellular transport along microtubules. Kinesin activity has been linked to various cellular functions such as vesicle transport, mitotic spindle formation, chromosome segregation, and cytokinesis. Structurally, all kinesins contain a motor domain with microtubule and nucleotide binding sites that utilize ATP to target cargo along microtubule filaments. KIF14 silencing experiments suggest that KIF14 plays a multi-functional role in mitosis and cytokinesis. KIF4A has been shown to be essential for cytokinesis.