Companies are testing a record 89 treatments on humans to fight cancer. These treatments combine antibodies from the body’s natural defense system with agents that fight cancer. They are testing what they call antibody-drug conjugates, or ADCs. Researchers describe ADCs as “guided missiles” in the fight against cancer. They are designed to target cancer cells and then release cytotoxins, substances that have a toxic or poisonous effect on the cells. ADCs are up to 10,000 times as powerful as most chemotherapy treatments. They also reduce damage to healthy tissue.