Hundreds of cancer-linked genes play a different role in causing disease than scientists had expected. So-called tumor suppressor genes have long been known to block cell growth, preventing cancerous cells from spreading. Mutations in these genes, scientists believed, thus allow tumors to flourish unchecked. Now, Howard Hughes Medical Institute (HHMI) Investigator and Gregor Mendel Professor of Genetics and of Medicine at Harvard Medical School Stephen Elledge (photo), PhD, and his team have uncovered a surprising new action for many of these defective genes. More than 100 mutated tumor suppressor genes can prevent the immune system from spotting and destroying malignant cells in mice, according to Dr. Elledge, also a geneticist at Brigham and Women’s Hospital, and colleagues, who reported their results online on September 17, 2021, in Science. “The shock was that these genes are all about getting around the immune system, as opposed to simply saying ‘grow, grow, grow!’” Dr. Elledge says. The Science article is titled “The Adaptive Immune System Is a Major Driver of Selection for Tumor Suppressor Gene Inactivation.”