The "cell cycle" describes discrete steps in the process of cell division. The progression is mediated by a series of gatekeeping biochemical activities that ensure complete replication of DNA, and surveil it for fidelity. Precise execution of cell cycle is necessary for normal growth and development. At the same time, loss of cell cycle coordination can lead to aberrant cell proliferation that can become genetically unstable, a condition recognized as cancer. Many drugs target the enzymes that control cell cycle progression, and several appear to be attractive candidates for future therapeutics. Spiro Rombotis of Cyclacel Pharmaceuticals describes targeting the cell cycle, along with new drugs that show promise in slowing, arresting, or possibly reversing some challenging subtypes of cancers.