GRM3 and breast carcinoma: CRISPR-mediated disruption or pharmacological blockade of GRM3 using LY95 significantly opposed the ability of MMTV-PyMT cells to reduce the amount of fibrillar collagen in organotypic plugs indicating that GRM3 is required for breast cancer cells to efficiently degrade the ECM in a 3D microenvironment (Fig. 5d).