Emma Dimery was 23 years old when she was diagnosed with stage 4 colon cancer. Over the next decade, she tried everything in vain: surgery, chemotherapy, radiation, and conventional immunotherapy. That changed in March 2023, when she received an infusion of tumor-infiltrating lymphocytes (TILs) edited with CRISPR at a key gene checkpoint, CISH. Since then, she has been in complete remission, with no detectable traces of the tumor.