An experimental treatment shrinks melanomas by pumping them full of interleukin-12, a protein that boosts the body's immune response against cancer. Developed by ZIOPHARM Oncology, the treatment has two steps: 1) injecting tumors with Ad-RTS-IL-12, a virus that has been engineered to make interleukin, and 2) controlling how much interleukin is made with a drug called INXN‑1001. A phase I clinical trial showed that this treatment increases white blood cells near melanomas and makes tumors flatter and smaller. These findings were presented at the American Society for Clinical Oncology's 2013 meeting. A phase II trial of this immunotherapy is underway in up to 15 patients.