Proper cell division is crucial for maintenance of healthy tissues and organs. There are multiple control mechanisms, or cell cycle checkpoints, that detect possible errors in copies of DNA (DNA replication) and stop the cycle until the error is repaired. These control mechanisms play an important role in regulation of the cell division. For example, in cancer cells, this regulation is compromised, as many types of cancer cells have mutations that allow them to skip the cell cycle checkpoints and allow damaged cells to divide and grow.