It is worth noting that STF31 hasbeen reported as an inhibitor of the glucose transporter 1 (GLUT1).53 GLUT1 inhibition by STF31 and DNAmethylation by Temozolomide showed synergistic effects in glioblastoma.54 Considering the known DNA-binding abilitiesof ruthenium complexes with open positions in their coordination sphere,55 the higher PI value in normoxia might resultfrom off-targets, such as GLUT1 inhibition and/or DNA binding of Ru-OH2. This evidence concerns the gene SLC2A1 and glioblastoma.