KIF2B is a kinesin-13 microtubule depolymerase essential for mitotic fidelity and spindle assembly 1. As a plus-end directed motor protein, KIF2B catalyzes microtubule depolymerization and localizes to centrosomes, spindle microtubules, and kinetochores, where it functions in chromosome 17 and attachment error correction 1. During prometaphase, KIF2B associates with CLASP1 at kinetochores to promote microtubule turnover and chromosome 17, then is replaced by an astrin-CLASP1 complex during metaphase to stabilize attachments 2. Polo-like kinase 1 (Plk1) phosphorylates KIF2B at threonine 125 and serine 204 to regulate both its kinetochore localization and activity in correcting erroneous kinetochore-microtubule attachments 3. KIF2B deficiency causes monopolar spindles, dramatically reduced chromosome 17 velocity (~80%), and cytokinesis failure 1. Clinically, KIF2B overexpression reduces chromosome 17 errors and promotes tumor growth in K-Ras-driven lung cancer, suggesting chr17 instability normally suppresses tumorigenesis 4. Protein abundance is regulated by SCF^Fbxw5-mediated proteasomal degradation during G2 phase 5.