AbstractAdoptive cell transfer (ACT) of tumor‐infiltrating lymphocytes (TILs) for melanoma is an example of the most successful cancer immune therapy. It achieves a durable complete response about ~20% of patients, and they might be cured. However, the ratio of patients with durable benefits is not high, and its complicated procedure prevents its diffusion. Therefore, many efforts to enhance the effect and simplify the protocol of TIL therapy have been made so far, resulting in the establishment of a simple and effective current TIL therapy that has been propagated to other institutes and countries. Moreover, TIL therapy and translational research using clinical samples derived from durable responders elucidate the important element for developing more effective cancer immune therapies in the future. This review introduced the brief history, attempts for the improvement and important findings elucidated by translational research of ACT for melanoma.