IL6 and glioblastoma: Previous studies have demonstrated enhanced production of IL-6 and IL-8 in various cancer cells such as pancreatic, ovarian and glioblastoma exposed to hypoxia, but our study demonstrates for the first time that normal epithelial cells down-regulate whereas predominantly, renal tumor cells upregulate interleukin expression under hypoxic conditions [22], [23], [24], [25].