It should be highlight the complexity of the regulatory path and the broad range of product types (cell therapy, gene therapy and tissue engineering products), including combination products. Entering the right path requires an early awareness of the end-product definition. Once defined, more technical challenges are to implement the correct assays to demonstrate (long-term) safety and efficacy (e.g., requiring validation of dedicated potency assays for often highly individualised, chimeric products). The field is still rapidly developing where the field of regulatory science (dialogue between academia and regulator) is pivotal to move the field forward. Upscaling requires often advanced (GMP) infrastructures close to the clinical setting as most products are still autologous (patient-derived) and not yet allogeneic (off-the-shelve) in nature .