IL2 and cancer: Adoptive cell transfer (ACT) is a treatment that uses a cancer patient’s own T lymphocytes from peripheral blood, activated and expanded ex vivo, and reinfused into patients pre-treated with lymphodepleting agents (e.g., fludarabine/cyclophosphamide), often in combination with appropriate growth factors stimulating their survival and expansion in vivo (i.e., IL-2) [79].