CCN2 and autosomal dominant polycystic kidney disease: Vasopressin has been shown to stimulate V2R/cAMP/PKA/ERK/YAP-mediated cell signaling in tubular epithelium, promote the expression and release of connective tissue growth factor (CCN2) and other YAP targets (PAI-1, AREG and MCP-1), and increase the number and activity of interstitial myofibroblasts and fibrosis in ADPKD kidneys (Figure 4) (Dwivedi et al., 2020).