However, the TX3868 and TX3095 GBM cell lines showed dose-dependent proliferative responses post-VD3 treatment, which could be attributed to an increased expression of 1,25-dihydroxy vitamin D3-24 hydroxylase (CYP24) following exposure to VD3 [30], suggesting that although these GBM cells could metabolize VD3, it did not affect the expression of VDR. This evidence concerns the gene CYP24A1 and glioblastoma.