1 Data and Format Mass spectra were searched against the UniProt protein sequence database with Protein Discoverer. Only the SwissProt section of Human UniProt was used with 20,197 entries. For all analyses we recovered the PSM abundance result from the Protein Discoverer in an excel spreadsheet which we converted to a tab delimited data table using a python script. This table is in long format with each PSM belonging to a run and a TMT channel. A 96-well plate provides sources for several TMTplex runs. Each TMTplex run was filtered and normalized separately which required reformatting the table into the wide form.