Regarding the metastatic potential of siGDF15-treated cells, a scratch assay revealed that the migratory ability of both brain cancer cell lines was impaired when GDF15 was reduced in the presence of mechanical compression (Figures 6C,D), while in uncompressed conditions GDF15 silencing impaired only the migration of A172 cells (Supplementary Figures 4A,B). This evidence concerns the gene GDF15 and brain cancer.