EGFR and breast cancer: The need for more physiologically realistic models is highlighted by the comparison of two-dimensional (2D) cell cultures with 3D breast-cancer-derived spheroids, which discloses how important pathways such as epidermal growth factor receptor (EGFR) and insulin-like growth factor I receptor (IGF-IR) influence cell behavior and extracellular matrix (ECM) macromolecular expression.