Other studies utilizing the 5/6 Nx model have shown that serum creatinine, urea, and proteinuria increased significantly, accompanied by intestinal barrier disruption, dysregulated mucosal Immunity, and decreased expression of HSP70 and claudin-1 in the colon, with increased pore-forming claudin-2 expression and apoptosis, promoting systemic inflammation and renal fibrosis (Yang et al., 2018; Kanemitsu et al., 2019). The gene discussed is CLDN1; the disease is renal fibrosis.