Unexpectedly, overall STAT3 phosphorylation level was increased in the ITE+PD1 group of glioma tissue, indicating that glioma cells might respond to other upstream factors of STAT3 that exist in tissue but not in the cell culture medium or non-cancerous cells such as macrophages/microglia might respond to ITE by activating STAT3. This evidence concerns the gene STAT3 and central nervous system cancer.