Table 1.

Classification of matrix metalloproteinases.

MMP classification			Enzyme substrates	Cell type/tissue secretion	References
Collagenases	Collagenase-1	MMP-1	Collagen types I, II, III, VII, and X	EVTs, decidua, and uNK	[39–42]
	Collagenase-2	MMP-8	Collagen types I and III	EVTs, decidua	[39, 43, 44]
	Collagenase-3	MMP-13	Collagen type I	EVTs, decidua	[39, 44–46]
Gelatinases	Gelatinase A	MMP-2	Collagen types I, III, IV, V, VII, and X; gelatin; fibronectin; and elastin	EVTs, decidua, and uNK	[39, 42, 44, 47–52]
	Gelatinase B	MMP-9	Collagen types I, III, IV, and V and gelatin	EVTs, decidua, and uNK	[39, 42, 44, 47–50, 52]
Stromelysins	Stromelysin-1	MMP-3	Collagen types III, IV, IX, and X; gelatin; laminin; fibronectin; and elastin	EVTs, decidua	[39, 44, 50, 53]
	Stromelysin-2	MMP-10	Collagen types II, IV, and V; fibronectin; and gelatin	EVTs, decidua, and uNK	[39, 44, 50, 54]
	Stromelysin-3	MMP-11	Collagen type IV	EVTs, decidua, and uNK	[39, 44]
	Matrilysin	MMP-7	Fibronectin and gelatin	EVTs, decidua, and uNK	[39, 41, 42, 44, 45]
	Matrilysin-2	MMP-26	Fibronectin and gelatin	EVTs, decidua	[39, 55, 56]
	Metalloelastase	MMP-12	Elastin and fibronectin	EVTs, decidua, and uNK	[39, 44, 57, 58]