MMP2 and neoplasm: Among MMP families, MMP-2 (the 72-kD type IV collagenase/gelatinase A) and MMP-9 (the 92-kD type IV collagenase/gelatinase B), which selectively degrade type IV collagen, a major component of extracellular matrix, are reported to be markedly associated with the invasion and metastasis of tumor cells [99].