These genes (FOS, HSPA1A, HSPA1B, MXD1, JUN, PTGS2, EGR1, PCK1, EGF, CETP, KL, SST, IGF1, SLC13A1, and PLCG2) were identified as significant co-differential genes associated with DKD and aging (Table 2). The gene discussed is PCK1; the disease is diabetic kidney disease.