STAT3 and glioblastoma: Immunofluorescence studies on GBM cells further confirmed the IL-22-induced STAT3 phosphorylation, and showed its nuclear localization in both studied GBM cell lines after 10 min (data not shown) and 30 min of treatment (Fig. 4A and 4B), demonstrating the STAT3 nuclear translocation in the presence of IL-22 (Fig. 4A and 4B).