By focusing on the highest annotated pathway cluster (enrichment score, 3.51) and its 12 related genes (Figure 1), two genes of interest, namely, MCP-1/CCL2 and ET-1, were selected for further verification at the mRNA and protein levels based on their established involvement in the early pathogenesis of diabetic- and non-diabetic kidney disease. The gene discussed is CCL2; the disease is diabetic kidney disease.