Among 25 biopsy samples (five patients with unknown AKI etiology and twenty patients with nephrotic syndrome; patient with AKI due to rhabdomyolysis excluded from analysis due to young age), PAX8 nuclear expression in the proximal tubuli was observed in 11 cases, which revealed some degree of interstitial renal fibrosis (IRF), (Figure 5A), followed by tubular atrophy in 10 cases (Figure 5B). The gene discussed is PAX8; the disease is Atrophy.