This project is intended to identify the compositions of the tissue matrix scaffold (TMS) generated from the extracellular matrix (ECM) of decellularized NON-SCID mice breast tissues (DBT). Since ECM is the physicochemical support for the cells living in the tissue microenvironment, it is important to know the protein contents within the ECM that are critical for extra- and intracellular signaling, cell growth, migration, cell-cell/ECM interactions. The LC-MS/MS data will serve as a foundation for the downstream applications of the TMS system, and be compared with those of the Matrigel mass spectrometry.