The immune system's hole-punch protein turns out to kill cancer cells all by itself

For decades, immunologists told a tidy story: a protein called perforin punches a hole in a cancer cell, then partner proteins called granzymes slip through the hole and do the killing. A team led by Weiping Zou and Ilona Kryczek at the University of Michigan's Rogel Cancer Center, with Harvard's Judy Lieberman, has now shown the story was missing its lead actor. In a study published in Cell, perforin alone — no granzymes needed — killed tumour cells by triggering an iron-driven form of cell death called ferroptosis, and patients whose tumours carried more perforin lived longer and responded better to immunotherapy. Knowing exactly which weapon does the work tells drug designers where to aim next.

SDG 3 · Good health and well-being — Mechanism: tech innovation