In a study of glioma, it was found that SPOCK1 and SPOCK3 can inhibit the invasiveness of glioma cells by suppressing membrane-type 1 matrix metalloproteinase (MT1-MMP)-mediated matrix metalloproteinase 2 (MMP2) activation, and that high level of SPOCK2 expression could abrogate the inhibition of MMP2 by SPOCK1 and SPOCK3 and increase the invasiveness of glioma cells (Nakada et al., 2001, 2003). Here, MMP14 is linked to central nervous system cancer.