Background: INCENP (inner centromere protein) is a component of the chromosomal passenger complex (CPC) which is a group of proteins that localizes to the centromere during specific stages of the cell cycle. The CPC is key regulator of mitosis that functions in spindle assembly, chromosome alignment, and segregation. INCENP contains a coiled-coil domain that interacts with microtubules and is required for the spindle-assembly checkpoint.