Members of this family are components of the mitotic spindle. It has been shown that Nuf2 from yeast is part of a complex called the Ndc80p complex. This complex is thought to bind to the microtubules of the spindle. An arabidopsis protein has been included in this family that has previously not been identified as a member of this family. The match is not strong, but in common with other members of this family contains coiled-coil to the C-terminus of this region.