In our previous report, a comparison of T cells generated from two methods commonly used in clinical trials showed that compared with OKT3/IL-2-stimulated T cells, CD3/CD28-Dynabead-stimulated T cells were more uniformly central memory cells with a significantly potent ability to control leukemia in Nalm6 mice model following intravenous infusion (Barrett et al., 2014). Here, IL2 is linked to leukemia.