Cancer researchers have spent decades staring at the same problem: the immune system can find cancer cells, but tumors keep slipping away. Why? A lot of it comes down to the tumor microenvironment—the neighborhood around a tumor where cancer cells essentially run a protection racket. Research from Carnegie Mellon University, published in Frontiers in Immunology in March 2026, suggests an old drug might help. Niclosamide has been around since the 1960s as a treatment for tapeworm infections. Now researchers are asking whether it could work against cancer too. What’s Going Wrong in the Tumor Microenvironment The area around a tumor isn’t just empty space. It’s full of activity, and cancer…