Extracellular matrix in most tissues is abundant in collagen and other proteins like collagen.

大部分组织中的细胞外基质,都富含胶原蛋白和其他类似蛋白

耶鲁公开课 - 生物医学工程探索课程节选

It turns out that one of the places that's been very fruitful to look for proteins that differ between cell populations is on the surface of the cell.

而事实证明,寻找能鉴别细胞种类的,特定蛋白的最佳位置,是在富含蛋白的细胞膜上

耶鲁公开课 - 生物医学工程探索课程节选