duete; see due, ty 2 ]. syn: duty, obligation refer to something a person feels bound to do. A duty often applies to what a person performs in fulfillment of the permanent dictates of conscience, piety, right, or law: one's duty to tell the truth; a parent's duty to raise children properly.
Mutations in the RB1 gene are responsible for most cases of retinoblastoma. RB1 is a tumor suppressor gene, which means that it normally regulates cell growth and keeps cells from dividing too rapidly or in an uncontrolled way.
Retinoblastoma: (Source: Genes and Disease by the National Center for Biotechnology) ... more about Retinoblastoma. Retinoblastoma: A very rare malignant tumor that originates in the retina. More detailed information about the symptoms, causes, and treatments of Retinoblastoma is available below.