In agreement with the previous cell viability experiments, the efficiency of U87MG cells to generate tumor cell colonies by anchorage-independent growth in a semi-solid medium was significantly reduced by knocking down E2F2. Both the total amount of colonies (≥100 μm) and the average size of the colonies were significantly lower when assaying U87MG cells subjected to E2F2 knockdown, compared with those of the control cells (P=0.0081 and P=0.0076, respectively) (Fig. 2). The gene discussed is E2F2; the disease is neoplasm.