According to the National Cancer Institute, interleukin-2 (IL-2) is a type of biological response modifier (a substance that can improve the body's natural response to infection and disease) that stimulates the growth of certain disease-fighting blood cells in the immune system.

These substances are normally produced by the body. When the treatment is effective, it works very well.

As you can see in the first graphic, the computed tomography (CT) photo shows a kidney tumor highlighted on the left in a red circle. After completing IL-2 therapy, the tumor appears to be gone (green circle).

One type of synthetic IL-2 is called Proleukin. This is the drug given in therapeutic doses to increase the efforts of the immune system to fight cancer cells.

IL-2 therapy is not appropriate for all patients with metastatic kidney cancer or melanoma. IL-2 therapy will only be effective for approximately 15 percent of the patients who are eligible for it. Ongoing research efforts around the world and at Roswell Park are working to boost the success rate and also to decrease some of the side effects.

Here is another example of IL-2 therapy at work. In the bottom picture, you see a "before" and "after" treatment of a patient with melanoma. The after photo on the right shows that multiple tumors are gone with little scarring.

For more information, please call 1-877-ASK-RPCI (1-877-275-7724).