Mechanisms to explain this oncogenic role range from ability to maintain pluripotency in early cell lineages10,11, promotion of epithelial-to-mesenchymal transition (EMT) in embryonic stem cells12, and geminin ability to control proper cytokinesis in G2/M/early G1-phases1,4 in normal human mammary epithelial (HME) cells, while cytokinesis failure and production of aneuploid, aggressive breast cancer cells when overexpressed13,14. The gene discussed is GMNN; the disease is breast cancer.