Similar as in the above-mentioned tumor models, PI3Kδ inhibition by idelalisib treatment of CLL patient-derived T-cells in vitro also resulted in reduced proliferation, expression of activation markers (CD69, CD25) (146), and cytokine production, including IL-2, TNFα, and IFNγ (146). This evidence concerns the gene IFNG and B-cell chronic lymphocytic leukemia.