An FDA panel has recommended that a revolutionary gene therapy treatment — CTL109 from Novartis and the University of Pennsylvania — be approved to fight a rare form of childhood leukemia, which would make it the first gene therapy treatment to reach the market, per the NYT.

Why it matters: It's a potentially game-changing step for cancer treatment. The traditional use of chemotherapy, essentially strong poison sent directly into the bloodstream, might become a thing of the past should gene therapy be proven effective.

• How it works: Millions of a patient's T-cells are removed and reengineered using a disabled form of HIV to become equipped to attack and destroy B-cells, which are a normal part of the immune system but become malignant when a patient has leukemia. The new T-cells are reintroduced to the patient's bloodstream where they become cancer "serial killers."
• The limitations: The time needed to reengineer the cells has been knocked down to 22 days from 4 months, but the treatment can only be performed at 30 to 35 approved medical centers. Plus, the initial side effects can be extremely harsh — with severe reactions — and longer-term side effects might still pop up.