When T24 cells with overexpression or silencing of TFCP2L1 were seeded on low attachment plates at clonogenic densities, followed by a 1‐week culture period, we found that TFCP2L1‐silenced T24 BC cells hardly produced tumor spheres with sharp edges; however, ectopic expression of TFCP2L1 or its co‐expression with CDK1 increased tumor sphere formation in comparison with cells transfected with the empty control (Fig 5F). The gene discussed is CDK1; the disease is breast cancer.