Other reports have also described the abnormal expression of matrix metalloproteinase genes, including MMP9 in cell lines from the liver cysts of ADPKD patients48, MMP2 and MMP14 in kidneys of PKD murine and rat models49, 50, 51, and higher serum MMP1 and MMP9 levels in ADPKD patients52. The gene discussed is MMP2; the disease is autosomal dominant polycystic kidney disease.