CNDP1 and diabetic kidney disease: Although the link between CN1 and DKD has been observed in several studies that found an association of CN1 genetic variants with the risk to develop DKD (Vardarli et al., 2002; Freedman et al., 2007; McDonough et al., 2009; Ahluwalia et al., 2011; Chakkera et al., 2011; Kurashige et al., 2013), CN1 concentration and activity levels have not been measured in large cohorts and assessed as potential diagnostic or prognostic markers.