该基因编码的蛋白序列相似，可能与视网膜母细胞瘤1（RB1）基因的产物功能相似rb1基因产物是一种肿瘤抑制蛋白，似乎参与细胞周期的调控，因为它在s-m期转化时磷酸化，在细胞周期的g1期去磷酸化。rb1蛋白和该基因产物均能与腺病毒e1a蛋白和sv40大t抗原形成复合物，sv40大t抗原仅与每个蛋白的未磷酸化形式结合。此外，两种蛋白都能抑制启动子中含有E2F结合位点的细胞周期基因的转录。由于其序列和生化特性与rb1蛋白相似，因此认为该基因编码的蛋白也可能是一种抑癌基因。已经发现了两个编码不同亚型的转录变体。[由RefSeq提供，2008年7月]
The protein encoded by this gene is similar in sequence and possibly function to the product of the retinoblastoma 1 (RB1) gene. The RB1 gene product is a tumor suppressor protein that appears to be involved in cell cycle regulation, as it is phosphorylated in the S to M phase transition and is dephosphorylated in the G1 phase of the cell cycle. Both the RB1 protein and the product of this gene can form a complex with adenovirus E1A protein and SV40 large T-antigen, with the SV40 large T-antigen binding only to the unphosphorylated form of each protein. In addition, both proteins can inhibit the transcription of cell cycle genes containing E2F binding sites in their promoters. Due to the sequence and biochemical similarities with the RB1 protein, it is thought that the protein encoded by this gene may also be a tumor suppressor. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jul 2008]