Why is it important to protect the tropical rainforests today in regard to the future struggle against cancer?

Answer:

More than half of the 3,000 plants that the National Cancer Institute has identified with potential cancer-fighting properties are found in rainforests, but less than 1% of the plants in the tropical rainforests have been tested for their medicinal properties. This means that potentially more than a hundred thousand plants with anti-cancer properties are out in tropical rainforests waiting to be tested. But if the plants go extinct before they are even tested, many potential drugs could be lost forever before they are even discovered.