MMP9 and juvenile polyposis syndrome: In all, fifteen proteins were elevated in PJI, including lactotransferrin, lipocalin, myeloperoxidase, calprotectin A8 and A9 subunits, cathepsin G, neutrophil elastase (ELA-2), eosinophil cationic protein (RNASE3), endoplasmic reticulum to nucleus signaling 1 (ERN1), matrix metalloproteinase-9 (MMP-9), lysozyme C, haptoglobin, lamin-B1, glycogen phosphorylase, liver form (PYGL), leucine-rich α-2-glycoprotein (LRG1).