IGFBP3 and pseudoxanthoma elasticum (inherited or acquired): However, PXE patients over 45 years showed a significant increase in serum IGFBP3 concentrations compared to appropriate healthy controls (PXE: 2543.0 ± 104.9 ng/ml; control: 2117.0 ± 147.6 ng/ml; p≤0.05) (Fig. 3B).