MIT teams published preclinical data showing polymer‑coated nanoparticles that deliver IL‑12 directly to ovarian tumors can convert immunologically cold lesions into responsive ones and, when combined with checkpoint inhibitors, eliminated metastatic disease in over 80% of tested mice. The nanoparticles localize cytokine activity within the tumor microenvironment to reduce systemic toxicity while promoting durable anti‑tumor immunity. Complementary MIT reports describe design principles for surface‑borne IL‑12 presentation that trick cancer cells into stimulating local immune activation and generating immunological memory against tumor antigens. The findings appear in Nature Materials and illustrate a targeted cytokine delivery strategy that may broaden immunotherapy indications for ovarian and other hard‑to‑treat solid tumors.