In the case of brain tumor tissue, for anterior brain RG-2 gliomas there was significant percent change in Gd-DTPA AUC with bradykinin B2 receptor agonist infusion (F4,36 = 9.62, p < 0.0001), and there was a statistically significant tumor volume effect (F1,36 = 4.68, p = 0.0372), i.e. the percent change in Gd-DTPA AUC was dependent on the glioma tumor volume. Here, BDKRB2 is linked to central nervous system cancer.