This lecture explores strategies for cancer immunotherapy, including blocking inhibitory pathways on T cells, increasing effector T cells through adoptive T cell therapy and vaccination, and how materials can enhance cancer vaccines. It also covers the use of biomaterials to activate the immune system, the challenges of immunotherapy, and the role of biopolymer-based expansion of tumor-specific T cells. The instructor discusses implantable cancer vaccines, synthetic cues for T cell stimulation, and the design of implantable alginate disks to boost T cell delivery in vivo. The lecture concludes with insights on sustained local delivery of immune cells using biomaterials and the potential of materials in cancer immunotherapy.