The gold standard for contemporary proteomics is LC-tandem MS (LC-MS/MS). Briefly, the LC column separates the peptides (typically generated by digesting proteins with trypsin) in the analyte prior to ionisation and subsequent MS analysis. In addition to recording the mass of the peptide ions, MS/MS technologies induce the subsequent fragmentation of these precursor ions. The masses of these fragment ions can therefore be used to delineate the amino acid sequence of the peptide. The availability of annotated protein sequence databases and algorithms that match the observed MS/MS spectra to protein entries have been crucial for the biomedical application of MS to study proteins.55,56 MS data can also be aligned to databases generated using DNA or RNA sequences to infer amino acid sequences. Current MS technologies now allow for the characterization of the ECM composition and turnover in CVD in unprecedented detail that is not possible using other techniques.2–5,52,57–59