Retinoblastoma protein and the cell cycle.

Deregulation of the cell cycle may contribute one of the primary mechanisms through which cancer arises. Eukaryotic cell division has been found to be a strictly controlled process, involving response to both positive and negative external signals and assessment of the cell's internal state. Several recent discoveries have strengthened and refined the theory that the retinoblastoma protein is involved in the decision between cell division and differentiation, and have begun to provide an outline of the nature of this involvement.