STAT3 and neoplasm: Pretreatment of monocytes with JSI-124, resulted in a significant reduction in STAT3 activity (measured by both STAT3 transcription factor assay (Fig. 2A, upper panels) or phospho-STAT3 intracellular immunostaining (Fig. 2B, left panel)) and in IL-10 production by the monocytes (Fig. 3, lower panels) in tumor cell:monocyte co-cultures.