Interestingly, in the context of this clinical success, a clear trend emerged quite early demonstrating that inherent features of TILs and TCR-engineered T cells resulted in durable and complete responses when treating solid cancer [11,15,214,215,216], while, for instance, the “poster child for CAR therapies” [217], the CD19-directed CAR, led to complete remissions of >88% when treating leukemia and lymphoma in clinical trials. Here, CD19 is linked to leukemia.