Launching a new chapter in the fast-moving cancer immunotherapy field, scientists have blended two cutting-edge approaches: CRISPR, which edits DNA, and T cell therapy, in which sentries of the immune system are exploited to destroy tumors. Two women and one man, all in their 60s—one with sarcoma and two with the blood cancer multiple myeloma—received CRISPR-altered versions of their own cells last year, researchers report online in Science this week.