 This study proposes a novel nanoplatform combining phototherapy and immunotherapy to treat metastatic cancer. It combines two components, a photosensitizing agent and a nanoparticle, to create a platform that can both deliver phototherapeutics and capture antigens from the tumor site. This platform is activated by a near-infrared laser, which allows for targeted delivery of the phototherapeutics while also enhancing the immunologically active properties of the platform. The platform has been tested on a poorly immunogenic, highly metastatic breast cancer cell line, and it was found to be effective at destroying the tumors and preventing their spread. Additionally, the platform was able to generate a tumor-specific immune response in the mice, leading to long-term survival and tumor-specific immunity. This article was authored by Meng Wang, Jun Song, Fief and Zhou, and others.