A subpopulation of retinoblastoma cells also displays immunoreactive ATP-binding cassette transporter glycoprotein G2, aldehyde dehydrogenase I, stem cell antigen-1, p63, and B lymphoma Mo-MLV insertion region 1 (BMI-1), indicating the properties of self-renewal and proliferation capacity of cancer stem cells [15]. The gene discussed is BMI1; the disease is retinoblastoma.