In addition, we have tested a range of T cell coengineering strategies for augmenting tumor control by ACT.41 61 66 67 For example, we showed that the enforced secretion of IL-15 by CAR-T cells in ACT studies against B16 melanoma not only improved T-cell fitness and function but was also associated with tumor immune microenvironment reshaping including NK cell activation and a reduced presence of M2-like macrophages.40 Here, IL15 is linked to melanoma.