Inhibition of Aurora B function by RNA interference or microinjection of blocking antibodies impairs the alignment of chromosomes at the equator of the mitotic spindle. This process of alignment is referred to as chromosome congression. The reason for this defect is a subject of ongoing study. Aurora B inhibition may lead to an increase in the number of syntelic attachments (sister chromatid pairs in which both sister kinetochores are attached to microtubules radiating from the same spindle pole). Intriguingly, expression of a dominant-negative and catalytically inactive form of Aurora B disrupted microtuble attachment to the kinetochore and prevented the association of dynein and centromere protein E (CENP-E) with kinetochores.