It is now widely appreciated that members of the matrix metalloproteinase (MMP) family of enzymes play a key role in cancer development and progression along with many of the hallmarks associated with them. The activity of these enzymes has been directly implicated in extracellular matrix remodeling, the processing of growth factors and receptors, the modulation of cell migration, proliferation, and invasion, the epithelial to mesenchymal transition, the regulation of immune responses, and the control of angiogenesis. Certain MMP family members have been validated as biomarkers of a variety of human cancers including those of the breast, brain, pancreas, prostate, ovary, and others. The related metalloproteinases, the A disintegrin and metalloproteinases (ADAMs), share a number of these functions as well. Here, we explore these essential metalloproteinases and some of their disease-associated activities in detail as well as some of their complementary translational potential. Anat Rec, 303:1557-1572, 2020.Matrix metalloproteinases (MMPs) are a multigene family of metal-dependent endopeptidases that play important and diverse roles in normal physiological and pathological processes. The classic domain structure of MMP family members can be found in Figure 1 (Roy et al., 2009). MMPs include an amino-terminal signal peptide required for secretion, a pro-domain that mediates latency via a cysteine-switch mechanism and a Zn 2+ -dependent catalytic domain that is responsible for enzymatic function. A majority of MMPs also contain a C-terminal hemopexinlike domain that provides substrate specificity. MMP activity is the rate-limiting step in extracellular matrix (ECM) degradation and it can regulate the activity of other proteases, growth factors, cytokines, and cell-surface ligands