Nanoparticle cancer treatment research. Scanning electron micrograph (SEM) of immune system cells being targeted by a vaccine-based immunotherapy using a novel nanoparticle system. The nanoparticles carry molecules that stimulate the immune response. The image shows dendritic cells (green) interacting with T cells (pink). The dendritic cells internalize the nanoparticles, process the antigens, and present peptides to the T cells which direct the immune responses. This work was carried out by researchers from the Texas Center for Cancer Nanomedicine (TCCN), USA. Image produced in 2013.