ABOUT THE COVER
Toward examining impacts of the tumor microenvironment on cancer drug delivery, Lee and colleagues applied Transparent Tissue Tomography (T3) as a new tool to visualize macromolecules in situ. The cover is adapted from a detail of a T3 snapshot of immunotherapy, showing a section of tumor excised minutes after injecting anti-PD-L1. Antibody (red) flows through the microvasculature (CD31⁺, cyan) and extravasates to bind to its target (PD-L1, magenta) on cancer cells (Her2⁺, green), reactivating cytotoxic T lymphocytes (CD8⁺, yellow) to restore anti-tumor immune response. For details, see article on page 213.