In the enhancing tumor parenchyma, the expression levels of MMP-2 (Fig. 5a, F = −2.951, P = 0.003) and VEGF in PCNSL (Fig. 5b, t = −5.103, P < 0.001), as well as MVD (Fig. 5c, t = −5.477, P < 0.001), were lower than those in GBM (Fig. 5d ∼ f), and these differences were statistically significant. The gene discussed is MMP2; the disease is glioblastoma.