Lung lysates were studied in a 3x6x1x3 design: three samples from a single donor, six fractions, only RPLC, and three injections. Heart lysates were studied in a 2x6x2x3 design: two donors, six fractions, both CZE and RPLC, and three injections. Small intestine and spleen were studied in a 1x6x2x3 design: one sample, six fractions, both CZE and RPLC, and three injections. Lysates were fractionated and prepared for mass spectrometry as described previously. Briefly, lysates were precipitated by adding four volumes of cold acetone and incubating at -80 °C for 1 hour. The precipitate was collected by centrifugation (20,000 × g, 30 min, 4 °C), and proteins were resolubilized in 1% sodium dodecyl sulfate (w/v). Total protein content was determined by BCA assay (Thermo Scientific). Samples were fractioned with the GELFrEE 8100 Fractionation Station (Expedeon). Protein samples (300 µg in 150 µL) were combined with 30 µL GELFrEE running buffer, and 8 µL 1 M DTT. The samples were incubated at 95 °C for 5 minutes, cooled to room temperature, and separated with a 10% GELFrEE cartridge following manufacturer's protocol. Six (four in the case of kidney samples) 150 µL fractions were collected and stored at -80 °C until immediately prior to analysis. On the day of analysis, fractions were thawed on ice and precipitated with methanol-chloroform-water as described. Pellets were resuspended in 10 µL 0.3% acetic acid (HAc) (v/v) and subjected to CZE-MS/MS. When CZE-MS/MS analysis was completed, the samples were diluted with 20 µL of buffer A (5% acetonitrile, 94.8% water, 0.2% formic acid) and subjected to RPLC-MS/MS analysis. If only RPLC-MS/MS was conducted, the pellets were resuspended directly in 30 µL buffer A.