MMP2 and central nervous system cancer: It was found that MMP-2 expression was significantly associated with high-WHO grade gliomas (n = 24, OR = 6.54, CI = 4.98–8.60; I2 = 0 %, P = 0.911) and poor overall survival (OS), while it did not correlate to age (n = 2, OR = 0.78, CI = 0.35–1.74; I2 = 0 %, P = 0.621) and gender (n = 2, OR = 1.15, CI = 0.51–2.62; I2 = 0 %, P = 0.995).