In the project four sets of label-free proteomics studies were performed to characterize the extra cellular matrix (ECM) proteome of differentially treated cells (see below). All cells were treated with sorbitol to induce the expression of PRSS35. Only in set IV PRSS35 is downregulated. For each set, three biological replicates were performed, which were each fractionated by SDS-PAGE into five fractions. Proteins were in-gel digested with trypsin and analyzed by DDA on an Exploris 480 mass spectrometer: