Geminin is a nuclear protein present in most eukaryotes and highly conserved across species, numerous functions have been elucidated for geminin including roles in metazoan cell cycle, cellular proliferation, cell lineage commitment, and neural differentiation. It is absent during G1 phase and accumulates through S, G2 phase and M phases of the cell cycle. Geminin levels drop at the metaphase-anaphase transition of mitosis when it is degraded by the anaphase-promoting complex. Geminin has also been found to be overexpressed in several malignancies and cancer cell lines, while there is data demonstrating that geminin acts as a tumor suppressor by safeguarding genome stability.