To elucidate whether Sp1-mediated CYP17A1 expression is involved in glioma development, we showed that Sp1 expression markedly increased as astrocytoma progressed to grade IV GBM (Supplementary Figure S9 and Supplementary Table S2) and that Sp1 strongly promoted glioma invasion (Supplementary Figures S10A–C). This evidence concerns the gene CYP17A1 and central nervous system cancer.