Researchers at the Texas Center for Cancer Nanomedicine (TCCN) have created particle-based vaccines for the treatment of cancer. The particles carry molecules that stimulate immune cells and cancer antigens (proteins) that direct the immune response. This scanning electron microscope image shows dendritic cells, pseudostained green, interacting with T cells, pseudostained pink. Dendritic cells internalize particles, provoke antigens and present peptides to T cells to direct immune responses.