Issues

Genetically-engineered mouse models often represent some of the most physiologically accurate models of cancer from which to understand the tumor microenvironment and with which to perform preclinical trials; however, tumors are often deep-seated and small animal imaging is a requisite for detecting and studying tumor progression. Presented on the cover is an example of multiplex optical and near-infrared imaging of a metastatic childhood rhabdomyosarcoma mouse model showing viable tumor cells in the left lower leg by firefly luciferase luminescence (green channel), pooling of an IR-820 dye due to loss of capillary integrity (red channel), and metal metalloprotease biochemical activity using a biochemically-activated contrast agent (blue channel). For details, see article by Schaffer and colleagues on page 2354.