CCN2 and diabetic kidney disease: 2012). Overexpression of CTGF is now widely accepted as a key marker of fibrotic activity. In diabetic kidneys the expression level of CTGF in the kidney is increased (Wang et al. 2001), and high glucose levels were also identified as an in vitro stimulus (Murphy et al. 1999). Losartan and spironolactone have been shown to decrease CTGF/CCN2 in human (Andersen et al. 2005) and experimental DKD (Han et al. 2006).