Adoptive cell therapy (ACT) recently became an important treatment modality for cancer . Since 2017, several chimeric antigen receptor (CAR)-T cell therapies approved by the FDA/EMA and more are expected to receive approval for clinical use. Currently, more than 250 clinical ACT trials are ongoing. Already in 2021, the market size was >$1 billion and is expected to grow tremendously to >$25 billion by 2030. ACT products require extensive ex vivo manipulation and expansion of patient derived T cells prior to reinfusion back into patients to attack cancer cells. Unfortunately, T cell exhaustion and loss of function after reinfusion form a major problem in currently used ex vivo expansion protocols. The solution. Dedicated tuning of T cells during ex vivo expansion to preserve their anti- cancer function and prevent exhaustion. In the body, T cells are activated by antigen presenting cells (APC) to initiate an immune response. As patient-derived APC are often immunosuppressed, much effort is spent on developing 'artificial antigen presenting cells' (aAPC) to expand immune cells for ACT. We developed a unique polymeric aAPC platform, termed immunofilaments, that provide a highly flexible-, scalable-, GMP compliant- and affordable- solution for robust production of T cells for ACT. Our initial findings indeed indicate that we can diminish T cell exhaustion and outcompete products currently used in the clinic for ex vivo T cell expansion. Tune-IT will validate the technical and commercial feasibility of this novel technology platform that exploits immunofilaments to significantly improve function and longevity of ACT products in patients. In Tune-IT, we will: 1) demonstrate that tuning of ex vivo cultured therapeutic T cells will prevent exhaustion and loss of tumor killing capacity after reinfusing T cells and 2) perform market and business case analyses to ensure commercial feasibility and market entry through Simmunext Biotherapeutics, a Radboudumc spin-off