In this thesis we identified several biomarkers that can predict diabetic kidney disease (DKD) progression and drug response. The identified biomarkers belong to multiple molecular pathways such as: inflammation, ECM degradation, fibrosis, energy metabolism and vascular function. The multiple pathways identified in this thesis indicate that DKD is a heterogeneous disease with a complex underlying pathophysiology. In addition, they provide insights in the underlying molecular mechanisms for how the drugs examined in this thesis may confer long-term kidney protection and they may even aid in identifying new drug targets for patients with DKD. Furthermore, the discovered and validated biomarkers and biomarker panels may pave the way for a personalized treatment approach and inform best (drug) treatment choices for individual patients.