The cover image illustrates the complex formation between amino-functionalized multi-walled carbon nanotubes (f-MWNT) and cytotoxic siRNA sequences shown to lead to prolonged survival of animals bearing human-lung carcinomas after intratumoral administration. The therapeutic efficacy of f-MWNT:siRNA complexes is compared in vivo against liposome:siRNA complexes. The direct comparison between carbon nanotubes and liposomes demonstrates the potential advantages offered by carbon nanotubes for the intracellular delivery of therapeutic agents in vivo. The present work may act as the impetus for further studies to explore the therapeutic capacity of chemically functionalized carbon nanotubes to deliver siRNA directly into the cytoplasm of target cells and achieve effective therapeutic silencing in various disease indications where local delivery is feasible or desirable. For more information, please read the Full Paper “Antitumor Activity and Prolonged Survival by Carbon-Nanotube-Mediated Therapeutic siRNA Silencing in a Human-Lung Xenograft Model” by K. Kostarelos et al. beginning on page 1176.