CCN1 and Nephroblastoma: The Cyr61/CCN1 gene encodes a matricellular protein that belongs to the CCN family comprising CCN1/Cyr61; CCN2/CTGF (connective tissue growth factor); CCN3/NOV (nephroblastoma overexpressed); and CCN4-6/WISP1–3 (Wnt-inducible secreted proteins) [1]–[3].