FN1 and melanoma: In invasive melanoma, ECM alterations are highly pronounced, with substantial basement membrane disruption and accumulation of collagen IV and laminin around large cell clusters instead of individual cells; dermal collagens I, III, and VI densely surround melanoma nests; while tenascin and fibronectin levels are significantly elevated across the papillary and reticular dermis, forming a supportive matrix conducive to tumor growth and invasion [59].