CD69 and leukemia: Transfer of CD39‐ CD69‐ cells into tumor‐bearing mice yielded significantly better tumor control than transferring CD39+ CD69+ cells, even at a tenfold concentration.[82] Similarly, characteristics of less‐differentiated CAR T cell products positively correlate with long‐term anti‐tumor activity and clinical response.[278] Stem‐like CAR T cells have shown better leukemia control while reducing adverse events.[279]