Skepticism might seem like an enemy of innovation, but when it comes to research, sometimes it’s the key. Dr. Johanna Joyce grew up in Ireland, earned her PhD at Cambridge, and used her “Irish skepticism” to create a major paradigm shift in cancer research at UC San Francisco and Memorial Sloan-Kettering. When everyone else was working to fight cancer by attacking the cancer cells themselves, they dismissed the white blood cells that surround tumors as “harmless garbage trucks.” But Joyce doubted how harmless they might be, and started critical studies in her lab to find out if attacking the white blood cells could treat the most common and most deadly forms of cancer. Joyce’s groundbreaking research turned into clinical trials that are attracting others to investigate similar methods. This bit of skepticism might just mark a major step toward curing cancer.