New Nature Biotechnology research showed that where mRNA is expressed after administration can strongly affect immune potency. In preclinical lymphoma models, hepatocyte detargeting strengthened T-cell immunity and did not rely on dendritic-cell expression as previously assumed. The Mount Sinai-led team used a microRNA-based approach to selectively silence mRNA expression in specific cell populations, including dendritic cells, hepatocytes, and muscle fibers. Silencing in dendritic cells did not impair T-cell priming, while detargeting hepatocytes reportedly increased immune responses. The work proposes a design principle for next-generation mRNA vaccines: optimizing the tissue distribution of antigen expression rather than focusing solely on dendritic-cell delivery. The findings also add practical guidance for how to build immunogens and delivery strategies that steer antigen presentation toward immune-activating pathways.