SOD2 and diabetic kidney disease: The impact of apolipoprotein E gene [19], growth arrest-specific 6 gene (Gas6) and their receptors Ax1 [20], polymorphism of the enzyme V16A of manganese superoxide dismutase [21], insulin gene [22], DQA1 and DQB1 haplotypes [23], HLA-DR3 and DR4 alleles [24] are investigated to clarify the reasons for the development of diabetic nephropathy.