In complex with KIF2C, constitutes the major microtubule plus-end depolymerizing activity in mitotic cells. Its major role may be to transport KIF2C and/or MAPRE1 along microtubules. Interacts with MAPRE1; this interaction is required for efficient accumulation at microtubule plus ends. Interacts with KIF2C at microtubule tips; this interaction increases the affinity of both partners for microtubule plus ends and is required for robust microtubule depolymerization. KIF2C phosphorylation by AURKA or AURKB strongly reduces KIF18B-binding. Present predominantly in the nucleus and to a lesser extent in the cytoplasm of interphase cells. During mitosis, found to be closely associated with astral microtubule plus ends emanating from the spindle pole during prometaphase and metaphase. Shows a prominent expression in the amygdala. Regulated in a cell cycle-dependent manner. Not expressed in the G1 phase. In G2, sequestered in the nucleus. Maximal levels seen at late G2/M phase and early prometaphase. Degraded at the metaphase-anaphase transition (at protein level). Belongs to the TRAFAC class myosin-kinesin ATPase superfamily. Kinesin family. Probable cloning artifact.