Diabetic nephropathy(DN) is a common diabetic microvascular complication, the underlying mechanisms involved in DN remain to be elucidated. We used microarrays to explore the global profile of gene expression for better understanding the molecular mechanism of diabetic nephropathy in type 2 diabetic db/db mice. Overall design: Ten-week-old male db/db mice and non-diabetic db/m littermates were housed for 12 weeks and sacrificed at 22 weeks of age, the kidneys were harvested for RNA extraction and hybridization on Affymetrix microarrays.