PGP and glioblastoma: On an other hand it has been reported that glioblastoma is characterized by aberrant activation of inflammatory responses; von Wedel-Parlow et al., reported that the pro-inflammatory cytokines interleukin-1 (IL-1b) and tumor necrosis factor-a (TNF-alpha) affect the expression of cerebral ABC-transporters in primary endothelial cells, the anti-inflammatory glucocorticoid hydrocortisone leads to a induction of Abcg2 (BCRP) and Abcc1 (MRP) mRNA in microvascular endothelial cells whereas Abcb1 (P-gp)gene expression is down-regulated (49).