the number and suppressive function of regulatory T cells was decreased by ATV in patients with rheumatoid arthritis. [29] Although both, hydrophilic and lipophilic statins demonstrated antitumor effects, hydrophobic APIs generally exhibit a higher permeability through the BBB by e.g. passive diffusion. However, lipophilic substances also tend to be substrates for P-glycoprotein, potentially reversing this effect [31, 32] . That this general trend is also true for statins was confirmed by Tsuji et al. , observing permeation of lipophilic lovastatin and simvastatin but not of hydrophilic pravastatin through an artificial BBB in vitro, later this was also confirmed in vivo . Important to note, among various statins, ATV is the most frequently reported one for causing adverse neurocognitive effects compared to less lipophilic statins which was associated with its increased permeability through the BBB. [35, 36] Therefore, we chose lipophilic ATV as potential cytotoxic API against various glioblastoma cell lines.