The cover shows the schematic of liposomal formulations for single drug–loaded nanoparticles of doxorubicin and carfilzomib (top and middle, respectively) and the carfilzomib and doxorubicin dual-loaded combination nanoparticle (bottom). Doxorubicin was chemically conjugated to a phospholipid via a labile hydrazone bond, while carfilzomib was passively loaded into the lipid bilayer. The dual drug–loaded combination nanoparticle demonstrated synergy in vitro and was more efficacious in inhibiting tumor growth in vivo than a combination of free drugs or single-agent liposomes. For more information, see the article by Ashley and colleagues beginning on page 1452.