What is the primary function of the extracellular matrix (ECM) in animal cells?

The extracellular matrix (ECM) is a complex network of macromolecules (proteins like collagen, fibronectin, and proteoglycans) secreted by animal cells that provides structural and biochemical support to the surrounding cells. Its primary functions include providing structural support, adhesion, cell-to-cell communication, regulating cell behavior (e.g., growth, differentiation), and holding tissues together. It plays a vital role in tissue organization and function.