MIT researchers reported polymer‑coated nanoparticles that deliver IL‑12 directly to ovarian tumors, markedly enhancing responses to immune checkpoint inhibitors in mouse models. Preclinical data in Nature Materials showed tumor eradication in more than 80% of treated animals and durable immune memory on rechallenge. The nanoparticle design concentrates cytokine activity within the tumor microenvironment while limiting systemic toxicity, enabling effective combination immunotherapy. Investigators demonstrated antigen‑specific memory, suggesting potential for long‑term tumor control. Authors highlight translational challenges including manufacturability, dosing strategies, and regulatory assessment of cytokine‑based nanomedicines. They propose this target‑and‑release approach as a platform to repurpose potent immunostimulants for hard‑to‑treat solid tumors.