TNF and neoplasm: RexRNA may play a crucial role in the context of tumor infiltration and progression as well, since under hypoxic conditions, GBM cells release elevated levels of rexRNA in comparison to non-tumor cells, and after exposure to rexRNA in vitro, the adhesion of tumor cells to the endothelium was shown to be increased due to extensive TNF-α release originating from tumor-infiltrating macrophages (Fischer et al., 2013).