In complex with KIF18B, constitutes the major microtubule plus-end depolymerizing activity in mitotic cells. Regulates the turnover of microtubules at the kinetochore and functions in chromosome segregation during mitosis. Plays a role in chromosome congression and is required for the lateral to end-on conversion of the chromosome-microtubule attachment. Interacts with CENPH. Interacts with MTUS2/TIP150; the interaction is direct. Interacts with MAPRE1; the interaction is direct, regulated by phosphorylation and is probably required for targeting to growing microtubule plus ends. Interacts with KIF18B at microtubule tips; this interaction increases the affinity of both partners for microtubule plus ends and is required for robust microtubule depolymerization. Phosphorylation by AURKA or AURKB strongly reduces KIF18B-binding. Associates with the microtubule network at the growing distal tip (the plus-end) of microtubules, probably through interaction with MTUS2/TIP150 and MAPRE1. Association with microtubule plus ends is also mediated by interaction with KIF18B. Centromeric localization requires the presence of BUB1 and SGO2. Testis. Localized to the meiotically active cells of the seminiferous epithelia in the testis. The microtubule tip localization signal (MtLS) motif; mediates interaction with MAPRE1 and targeting to the growing microtubule plus ends. Phosphorylation by AURKB, regulates association with centromeres and kinetochores and the microtubule depolymerization activity. Ubiquitinated. Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Kinesin family. MCAK/KIF2 subfamily.