p27 and Leukemia: Cell Cycle and Beyond

Cell division is the foundation to development and the regulation of cell cycle progression is therefore of paramount importance to the living organisms. Primary control of cell cycle is achieved by an array of cyclins and cyclin dependent kinases (CDKs). The functions of these cyclin-CDK complexes are again regulated by a host of cyclin dependent kinase inhibitors (CDKI). Till date CDKIs are broadly classified into two groups-INK4 family (p15, p16, p18, and p19) and the cip/kip family (p21, p27, and p57). Collectively these CDKIs regulate the progression from G1 to S phase of cell cycle. This review summarizes the functions of p27 while highlighting its emerging roles in leukemia.