In 1987, they further conducted a pilot clinical study that demonstrated the safety and feasibility of autologous TIL adoptive transfer, with improvements observed through dose escalation of TIL quantity, IL‐2 in patients with lymphodepletion preconditioning using cyclophosphamide treatment.[34] They reported the first clinical trial of TIL therapy for metastatic melanoma in 1988[35] and further summarized the clinical findings in 1994.[36] In these clinical studies, TIL cultures were produced in 6000 IU ml−1 IL‐2 until an average of over 1 × 1011 lymphocytes was achieved. Here, IL2 is linked to metastatic melanoma.