Cell & Gene Therapy Insights 2026; 12(1), 87–92 DOI: 10.18609/cgti.2026.011 In vivo CAR therapies are rapidly emerging as a strategy to address the scalability, access, and toxicity limitations associated with conventional ex vivo CAR-T cell products. This article reviews viral and LNP–RNA platform technologies, emerging clinical evidence, and key safety and regulatory considerations relative to established CAR-T and immune cell engager approaches.