CD9 and glioblastoma: Furthermore, the 76 patients with GBM that showed > 2.0-fold up-regulation of CD9 showed a 55% shorter median survival compared to the intermediate patient group, as those with CD9 gene expression between 2.0-fold up-regulated and 2.0-fold down-regulated (Figure 5B, right; 19 months vs. 42 months, respectively; p = 0.02).