In DKD, although there is some discrepancy between studies possibly due to the analysis at different disease stages, PGC1α activity is considered to be increased in the early stage of diabetes, as demonstrated in 8-week-old db/db mice, followed by a decrease in activity at later stages, as demonstrated in pretransplant patients and mice 24 weeks after diabetes induction with STZ injection [8,16,18,19]. The gene discussed is PPARGC1A; the disease is diabetes mellitus.