and is characterized by rapid cell proliferation and -migration in vitro and in vivo . The GBM6840 cells were highly sensitive to ATV with an IC 50 value of ~8 µM after 48 h treatment, irrespective of whether ATV was dissolved in DMSO or formulated with A-pBuOzi-A (Figure ; for representative examples of the original FACS results, the reader is referred to Figure ). Importantly, neat A-pBuOzi-A did not cause cytotoxicity (viability > 80 %) up to high polymer concentrations of 10 g/L (Figure ; for comparison: [A-pBuOzi-A] = 50 mg/L @ IC 50 (A-pBuOzi-A/ATV), Figure ). We did not observe an effect of low ATV concentrations (2.5 or 5 µM) on the transwell-migration of GBM6840 cells towards epidermal growth factor (a prototypical chemoattractant for glioblastoma cells) even after 73 h of ATV treatment (Figure ). These ATV concentrations were chosen because they did not cause a substantial loss of cell viability (Figure ). Thus, ATV appears to primarily affect GBM6840 cell viability, but not mobility.