ZW10 is an essential component of the mitotic checkpoint that prevents premature mitotic exit and ensures accurate chromosome 11 1. The protein functions as part of the RZZ complex (Rod-Zwilch-ZW10), which is crucial for recruiting dynein-dynactin and Mad1-Mad2 complexes to kinetochores during mitosis 2. ZW10 serves dual roles depending on cell cycle phase: during mitosis, it participates in spindle assembly checkpoint signaling, while during interphase, it regulates membrane trafficking between the endoplasmic reticulum and Golgi apparatus as part of the NRZ complex 3. The protein's mitotic function is regulated by PLK1 phosphorylation at Ser12, which controls ZW10-Zwint1 interactions and fine-tunes chromosome 11 timing 4. Loss of ZW10 results in checkpoint failure, premature mitotic exit, and chromosome 11 defects with lagging chr11 1. In interphase, ZW10 works with RINT-1 to facilitate ER-Golgi transport, and its Golgi localization correlates with centrosomal dynactin accumulation 56. The RZZ complex represents a metazoan-specific elaboration of the spindle checkpoint machinery, as these proteins lack yeast homologs 1. Recent studies suggest potential involvement in cancer susceptibility through DNA repair pathways 7.