Ionic fluxes and corresponding cell volume dynamics are established aspects of cell division. How calcium fluxes impact mitosis, though, is poorly understood, and studying how calcium fluxes modulate tumor cell proliferation may unveil novel therapeutic targets. In their study on page 852, Li and colleagues employed calcium and chloride imaging, electrophysiological, and immunohistochemical methods to interrogate how calcium fluxes affect proliferation in a glioblastoma cell line. The authors discovered that intracellular calcium flares occur in the transition from anaphase to telophase, activating calcium-dependent chloride channels. Subsequently, chloride fluxes promote cell swelling necessary to complete mitosis. The cover features a raster plot depicting calcium dye fluorescence in regions of interest over time. This study is also highlighted on page 785.