Cell and gene therapies, most notably CAR-T (chimeric antigen receptor) cells, are becoming increasingly important in cancer treatment. They are central to CellAction (Cell therapy Acceleration and Innovation), the brand-new Paris-Saclay Cancer Cluster (PSCC) platform at Institut Curie. CellAction's medical-scientific expertise and exceptional facilities make it a uniquely integrated structure in France. Thanks to public-private collaborations, projects can be launched to accelerate the development of innovative anti-cancer drugs, from basic research to their transfer to the clinic and to patients.