Because interleukin (IL)-2 drives CD8+ T cells toward an ‘effector’ phenotype, which confers poor anti-tumor performance in some models, reducing IL-2 signaling favors the production of memory CD8+ T cells. A new strategy for reducing IL-2 signaling is to conjugate IL2Ra siRNAs to a 4-1BB-binding oligonucleotide aptamer. Since 4-1BB is expressed on activated CD8+ T cells, this approach was designed to decrease IL-2 signaling...