Retinoblastoma-Binding Protein 2: A retinoblastoma binding protein that is also a member of the Jumonji-domain histone demethylases. It has demethylation activity towards specific LYSINE residues found on HISTONE H3.Retinoblastoma Binding Proteins: A family of endogenous regulatory proteins that associate with RETINOBLASTOMA PROTEIN via a specific high-affinity binding domain. Members of this family of proteins are often found associated with histone-modifying enzymes and protein complexes that regulate gene expression.Retinoblastoma: A malignant tumor arising from the nuclear layer of the retina that is the most common primary tumor of the eye in children. The tumor tends to occur in early childhood or infancy and may be present at birth. The majority are sporadic, but the condition may be transmitted as an autosomal dominant trait. Histologic features include dense cellularity, small round polygonal cells, and areas of calcification and necrosis. An abnormal pupil reflex (leukokoria); NYSTAGMUS, PATHOLOGIC; STRABISMUS; and visual loss represent common clinical characteristics of this condition. (From DeVita et al., Cancer: Principles and Practice of Oncology, 5th ed, p2104)Retinoblastoma Protein: Product of the retinoblastoma tumor suppressor gene. It is a nuclear phosphoprotein hypothesized to normally act as an inhibitor of cell proliferation. Rb protein is absent in retinoblastoma cell lines. It also has been shown to form complexes with the adenovirus E1A protein, the SV40 T antigen, and the human papilloma virus E7 protein.Retinal Neoplasms: Tumors or cancer of the RETINA.Genes, Retinoblastoma: Tumor suppressor genes located on human chromosome 13 in the region 13q14 and coding for a family of phosphoproteins with molecular weights ranging from 104 kDa to 115 kDa. One copy of the wild-type Rb gene is necessary for normal retinal development. Loss or inactivation of both alleles at this locus results in retinoblastoma.Eye Neoplasms: Tumors or cancer of the EYE.