CCN1 and cancer: Because cell culture in three-dimensional (3D) extracellular matrix (ECM) is considered as a more relevant model system to evaluate cancer cell behavior [39, 40], we evaluated the size, form, and E-cadherin distribution of colonies formed by MCF-7/pBABE, MCF-7/CCN1, MCF-7/D125A-CCN1, and MCF-7/TM-CCN1 cells cultured in Matrigel®.