Inside Back Cover

The inside back cover picture highlights organic π‐radical materials, which feature delocalized spin electrons and hold great promise for versatile biomedical theranostics. This article systematically summarizes recent advances in π‐radical‐based platforms for fluorescence imaging, photoacoustic imaging, photothermal therapy, photodynamic therapy, and photo‐immunotherapy. In addition, the remaining challenges and emerging opportunities for the phototheranostic applications of these materials are critically discussed. Further details can be found in the article by Wang et al . on pages 3935—3957. image