MAPK3 and malignant glioma: Several MMP genes are inducible by extracellular stimuli, which activate the AP1 transcription-factor complex through pathways involving MAPKs (ERK1/22, JNKs and p38) and PKC; PKC is also known to have a function in increasing MMP9 expression by malignant glioma cells (Yabkowitz et al, 1999) through cytoskeletal changes and NF-κB (Chintala et al, 1998).