Therapy flags DNA typos to rev cancer-fighting T cells

Disabled spell-checker identifies patients who may benefit from immune therapy

Keytruda

UNLEASHED  An antibody sold as the drug Keytruda helps turn on cancer-fighting T cells. Tumors (red) can use PD-1 proteins (yellow, orange) to lock onto T cells (white) and shut them down. The antibody blocks PD-1 proteins, freeing T cells to attack the cancer.

Courtesy of Merck & Co.

Mutations that prevent cells from spell-checking their DNA may make cancer cells vulnerable to immunotherapies, a new study suggests.