ELANE and alkaline phosphatase measurement: Two other proteins proposed as biomarkers in PI were also identified: neutrophil collagenase/MMP-8 (P22894) upregulated 1.1x in AP, 1.82x in CP, and 9.7x in PI and neutrophil elastase (P08246) upregulated 2x in AP, 6.5x in CP, and 12.8x in PI.