VIP and glioblastoma: Pituitary adenylate cyclase-activating polypeptide and VIP are widely expressed inperipheral tissues, CNS and in a wide variety of human tumors, including GBM (Robberecht et al., 1993, 1994; Oka et al., 1998; Reubi et al., 2000; Juarranz et al., 2001; Isobe et al.,2003).