MMP9 and melanoma: Specific proteases like MMP-2, MMP-9, MMP-13, and MT1-MMP are often upregulated in the melanoma stromal microenvironment, where they degrade type I collagen fibers and basement membrane components like collagen IV, elastin, and laminin, operating a targeted ECM proteolysis that smooths the way for melanoma cells to invade surrounding tissue [58,59].