What is the role of the retinoblastoma protein in cell-cycle regulation? Is the retinoblastoma gene a tumor-suppressor gene or an oncogene?

The retinoblastoma gene, also known as the RB1 gene, encodes the Rb protein. Since the Rb protein functions in regulating cell-cycle progression by inhibiting the activity of transcription factors responsible for promoting cell division, its loss or inactivation can lead to uncontrolled cell proliferation. This characteristic makes the retinoblastoma gene a tumor-suppressor gene, as its normal function is to suppress the development of tumors by regulating the cell cycle. Mutations or loss of function in the RB1 gene can lead to various cancers, including retinoblastoma, a childhood cancer of the eye. An oncogene, on the other hand, is a gene that, when mutated or overexpressed, contributes to the formation or progression of cancer by promoting unregulated cell division. So based on the role of the retinoblastoma protein in cell-cycle regulation and its function in suppressing tumors: The retinoblastoma gene is a tumor-suppressor gene.