Britain aims to make chemotherapy a treatment of the past by funding a DNA mapping project to identify the genetic codes responsible for cancer and rare diseases, Prime Minister David Cameron said Friday.

With such information, doctors could provide therapies targeted at specific individuals and forms of cancer, eliminating the need for treatments like chemotherapy that cause widespread destruction in the body in an effort to destroy cancer cells.

“I believe we will be able to transform how devastating diseases are diagnosed and treated,” Cameron said as he announced a series of investments of more than $500 million across government, industry and charities, the BBC reported.

“I am determined to do all I can to support the health and scientific sector to unlock the power of DNA, turning an important scientific breakthrough into something that will help deliver better tests, better drugs and above all better care for patients,” the prime minister said.

The four-year project will allow scientists to decode 100,000 human genomes, a person’s unique DNA code, said a press release by Genomics England — a company owned by the U.K. Department of Health — on Friday. Genomics England will work alongside California-based Illumina on the project.

Cameron said that all of the genomes, taken from British patients with rare diseases and cancers, would be mapped by 2017. Scientists decided to focus the project on these illnesses because they believe gene therapy has great potential in both categories, Genomics England said on its website dedicated to “The 100,000 Genomes Project.”

Cancer begins when genes within normal cells begin to change, eventually causing people’s DNA to mutate and allowing a tumor to grow and metastasize, or spread throughout the body, Genomics England explained. Scientists can detect precise changes if they can compare DNA from the tumor with that of the patient’s normal cells, informing doctors as to the most effective treatment — which is what they hope this project will allow them to do.

“Twenty years from now academics and industry will have developed therapies which can be targeted at you and specific forms of cancer,” Jeremy Farrar of the U.K. health charity Wellcome Trust said, according to Sky News.

“We will look back in 20 years’ time, and the blockbuster chemotherapy drugs that gave you all those nasty side effects will be a thing of the past.”

Cancer cases are expected to rise 57 percent in the next 20 years, the World Health Organization said in February, making research like the 100,000 Genomes Project more crucial than ever.

Over the past decade in the U.S., costs of cancer treatments have skyrocketed to an average of $10,000 per patient per month without a corresponding increase in effectiveness. Critics accuse doctors of overprescribing expensive treatments like chemotherapy even when the costs to quality of life outweigh the benefits — such as in late-stage cancer patients who are unlikely to survive even with the treatment.

Genomics England will also focus on rare diseases because they are at least 80 percent genetic. Understanding the genome sequences associated with those diseases can help researchers identify their causes and find targeted treatments just as they plan to do in cancer patients, Genomics England’s website said.

“As our plan becomes a reality,” said Cameron in a press release, “I believe we will be able to transform how devastating diseases are diagnosed and treated in the [National Health Service] and across the world, while supporting our best scientists and life science businesses to discover the next wonder drug or breakthrough technology.”

