IFNG and neoplasm: When autologous tumor material from patients is available, one can test the tumor reactivity of the generated TIL product in vitro by co-culture of the TIL with the autologous tumor cell lines or tumor digest, with as read-out the production of effector cytokines, such as IFN-γ and TNF-α, or degranulation markers (such as CD107) by the T cells.