This model allows us to use a physiologically relevant cell system to determine how the sole expression of the oncogenic PAX3-FOXO1 can initiate a cascade of events, both direct and downstream, over a series of proliferation events, to contribute to the initial stages of tumor development with respect to aneuploidy and overcoming aneuploidy-dependent proliferative defects. The gene discussed is FOXO1; the disease is neoplasm.