A History of Cancer Research: G₁/S Transition and the Retinoblastoma Pathway

Basic research that established how the cell cycle is regulated has been critical to our understanding of carcinogenesis and paved the way for new treatments like palbociclib and ribocilib. Mitosis was first observed almost 150 years ago, and the phases of the cell cycle were defined midway through the twentieth century. Subsequent studies in yeast, frogs, mice, and human cells identified the molecular machinery that controls entry into the cell cycle, including cyclin-dependent kinases, their regulators, and the product of the retinoblastoma (RB) gene. In this excerpt from his forthcoming book on the history of cancer research, Joe Lipsick looks back at the work that discovered these key molecules and mapped the RB pathway that controls the G₁/S transition.