Neutrophil collagenase, also known as matrix metalloproteinase-8 (MMP-8) or PMNL collagenase (MNL-CL), is a collagen cleaving enzyme which is present in the connective tissue of most mammals.[1] In humans, the MMP-8 protein is encoded by the MMP8 gene.

However, the enzyme encoded by this gene is stored in secondary granules within neutrophils and is activated by autolytic cleavage. Its function is degradation of type I, II and III collagens. The gene is part of a cluster of MMP genes which localize to chromosome 11q22.3.