MMP11, also known as stromelysin 3, is overexpressed in the stromal cells of invasive breast carcinomas but not in the stromal cells surrounding benign breast fibroadenomas. MMP11 is secreted in its proenzyme from and the zymogen has a mass of 64 kDa. The enzyme is rapidly activated to a 58 kDa form, a 45-47 kDa size, then to a 28 kDa final active form. MMP11 is not constitutively produced by most cell types. It has been found in lung fibroblasts and gingival fibroblasts when stimulated with EGF, as well as breast tumor and osteocarcinoma cell lines.Synonyms: MMP11, Matrix metalloproteinase-11, SL-3, ST3, STMY3, Stromelysin-3