IL2 and leukemia: In lymphocytic leukemia, a hematologic tumor highly resistant to activated Vγ9Vδ2 T cells, IL-2 or IL-15, and TCR stimulation upregulates the expression of NK receptors NKp44, NKp46, and NKp30 on Vδ1+ T cells, allowing their acquisition of cytotoxicity against leukemia cells (26).