IL10 and central nervous system cancer: In order to replicate a tumor endothelial environment we utilized several cocktails of conditioned media from tumor cell lines (LLC (lung cancer), B16 (melanoma), RM-1 (prostate cancer), GL-261 (glioma), 4T1 (breast cancer)), as well as tumor associated cytokines (PGE-2, TGF-beta, and IL-10).