This study identifies POGZ as a key protein that controls how HP1α — a protein involved in packaging DNA — detaches from chromosomes during cell division (mitosis). Unlike most HP1-binding proteins, POGZ uses a zinc-finger-like motif to bind HP1α and compete with other interaction partners, destabilizing HP1α’s hold on chromatin. The researchers also found that POGZ is required for the proper activation and removal of Aurora B kinase from chromosome arms during mitosis. These findings establish POGZ as a critical link between HP1α dissociation and Aurora B kinase activation in dividing cells.