MMP8 degrades fibrillar collagens types I, II, III, aggrecan, serpins and alpha 2 macroglobulin. The substrate specificity of collagenases is variable: MMP1 degrades type III collagen more efficiently than type I or type II collagen, whereas MMP8 is more potent in degrading type I collagen than type III or type II collagen. Unlike other members, MMP8 is expressed exclusively in inflammatory conditions. MMP8 is highly expressed in the postpartum uterus, and it is thought to be involved in the postpartum involution of the uterus. MMP8 is also the predominant collagenase expressed in ulcers and healing wounds. MMP8 is very similar to MMP1, sharing 57 % amino acid identity. MMP8 is heavily glycosylated, and the zymogen has a mass of 85 Kd. The zymogen is quickly activated to the 64 Kd form, and this breaks down to a cascade of active forms.