NID1 and autosomal dominant polycystic kidney disease: Of the 18 genes of cell adhesive ECM glycoproteins expressed in the ADPKD kidneys, ADPKD fibroblast cluters were the major expressors of 9 genes including fibronectin (FN1), laminin subunit α4 (LAMA4), tenascin-XB (TNXB), thrombospondin-1 (THBS1), THBS2, biglycan (BGN), versican (VCAN), and nidogen-1 (NID1), compared to other renal cell types (Fig 1B).