IFNγ neutralization strongly counteracts the anti-apoptotic effect of activated T cell secretome on primary human CD34+ CML stem/progenitor cells during the first 36 hours, while at later time-points, simultaneous IFNγ and GM-CSF neutralization partially blocks the anti-apoptotic effect. This evidence concerns the gene CSF2 and chronic myelogenous leukemia, BCR-ABL1 positive.