The ability of BTZ to penetrate the blood–brain barrier has been debated; therefore, we performed intratumour biodistribution analyses and demonstrated that intraperitoneally (i.p.)-administered BTZ did cross the blood–brain barrier and could be detected in greater concentrations in the tumour-bearing mouse brains (42.54 ± 11.86 ng/g tissue) compared to healthy mouse brains with an intact blood–brain barrier (6.06 ± 1.15ng/g tissue; p < 0.01, Figure 5L). Here, CASC3 is linked to neoplasm.