As with MAP2 vs. GFAP, α-SMA and GFAP would not be expected to overlap, except perhaps at sites where astrocytes and glioma cells touch pericytes (68, 69); accordingly, we chose GFAP-positive and α-SMA-positive ROIs that were far apart from α-SMA and GFAP staining respectively, as well as double negative ROIs that exhibited neither. This evidence concerns the gene ACTA1 and central nervous system cancer.