STAT1 and neoplasm: This includes the attenuation of functional STAT3 by the STAT3β isoform, which is expressed in response to specific cytokine stimulation and by G-CSF secreted from myeloid cells during maturation and can abolish the activation of downstream targets and upregulate tumor cell apoptotic pathways that involve FAS—that is primarily induced by IFN-γ STAT1 activation [167].