STAT3 and neoplasm: We previously showed that STAT3 is phosphorylated at Y705 in GICs isolated from the GBM6, GBMX10, GBMX16 and GBMX39 PDXs, and that the JAK tyrosine kinase inhibitor WP1066 blocks Y705-STAT3 phosphorylation and inhibited subcutaneous tumor growth by GBM6 GICs [11].