When CD133+ CSC lines derived from primary astrocytic GBM were treated with up to 500 μM TMZ over different periods of time (2 d and 42 d), there was a dose-dependent reduction of CD133+ cells (by 80%), cell proliferation (by up to 100%), as well as clonogenicity and tumorigenicity (by up to 100%), whereas cell death did not exceed 6%. This evidence concerns the gene PROM1 and glioblastoma.