Using the CAM model and a murine orthotopic brain transplant model, reduced expression of IRE1 in glioma cells downregulates pro-angiogenic factors (VEGF-A; Interleukin-6 (IL-6)) and upregulates anti-angiogenic factors (such as SPARC and Decorin) linked to mesenchymal differentiation, tumor invasion and VCO (71). This evidence concerns the gene IL6 and central nervous system cancer.