Abstract: Type 2 diabetes is one of the most common diseases. In the year 2030 366 million patients are expected, which is a doubling in comparison to the year 2000. Besides a defective regulation of the glucose metabolism patients suffer from diseases of the kidney and the brain, which are named as diabetic nephropathies and diabetic neuropathies, respectively. Worldwide large efforts are undertaken to understand the causes of this disease. There is evidence, that a dysfunctional HNF4a plays an important role in the onset of diabetes. With the help of molecular biological and molecular genetic methods new HNF4a target genes (RSK4 and PAK5) were identified. These two genes encode for kinases. In a diabetic animal model RSK4 and PAK5 were selectively regulated. The identification of these genes and their fundamental importance for a therapy of type 1 and/or type 2 diabetes and/or nephropathies and/or neuropathies, including diabetic nephropathies and diabetic neuropathies is described.