Since only IFNγ (one of the most abundantly secreted soluble factors of activated T and NK cells), but not IFNα, tumor necrosis factor α, IL6, IL12, granulocyte-macrophage colony-stimulating factor (GM-CSF) or soluble CD40 ligand exerted an anti-apoptotic effect on TKI-treated CML cells, the authors suggested IFNγ as the key anti-apoptotic factor of the activated T and NK cell secretome. Here, CSF2 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.