The CART-SIE study, sponsored by Professor Paolo Corradini at the Fondazione IRCCS Istituto Nazionale dei Tumori in Milan, aims to evaluate the real-world feasibility, efficacy, and safety of CAR T-cell therapy in patients with various types of lymphoma, including DLBCL, PMBCL, MCL, and FL. This observational study is crucial as it will provide insights into the effectiveness of commercially available CAR T-cell products in Italy, potentially influencing treatment guidelines and reimbursement strategies. Given the increasing adoption of CAR T-cell therapies in oncology, the outcomes of this study could enhance competitive positioning for existing CAR T products and inform future product development and market entry strategies.