This review of retinoblastoma reflects the wide distribution of scientific interest in this disease. A relatively small number of publications this year dealt with traditional clinical concerns, in part because the collected manuscripts of the most recent International Retinoblastoma Meeting (held in October 1990) have not yet been published. The veritable explosion of information about the gene predisposing to retinoblastoma, RB1, reflects the power to advance biologic understanding that exists when a disease gene is cloned. This gene has been particularly valuable because it appears to occupy a key position in the cell cycle, perhaps regulating the critical choice between proliferation and differentiation. Besides initiating retinoblastoma, RB1 mutations are also important in all cancers.