Figure 1.

Representing illustrations of BBB and BTB. (A) A brain bearing glioblastoma (brown with orange border) with an invisible infiltrating region approximately 2 cm around the lesion (circled in red representing the region of recurrence after surgical excision). (B) The BBB in association with other cells present in the healthy brain microenvironment; the right side represents the cross-section of the cerebral vessels. (C) The BTB in the core of a glioblastoma; the right side represents the cross-section of the cerebral vessels. Note that TJs are disrupted, and ABC transporters (P-glycoprotein) are relatively increased in the BTB compared to the BBB.