MMP7 and cyst: After adjusting for age, serum MMP-7 demonstrated a significant positive correlation with both the mean relative cyst diameter (1.85 ± 1.27, r = 0.404, p < 0.001) and mean relative cyst length (3.28 ± 1.58, r = 0.402, p < 0.001, Fig. 3) in all CDC patients.