Specialized proteins called cell cycle regulators, such as p53 and p21, regulate the progression of the cell cycle from one phase to the next. This progression through the checkpoints is strictly regulated and usually works without error. When errors do occur, they can have catastrophic consequences, including cancer. How did this study lend new evidence to our understanding of how genes regulate the cell cycle, giving us a better chance of developing successful cancer treatments

The change in the genes p53 and p21 results in deficits in checkpoints that result in cancer of various types. The G2-HM checkpoint deficits can be exploited in the development of targeted treatment.

A mutation in the above normal functioning of p53 can lead to the progression of damaged cells to mitosis which leads to cancer. So therapeutics which target any of these checkpoints can lead to developing a treatment for cancer.

multiply it by 5 in order for you to understand i cant give an exact answer.