Masson’s staining and Sirius Red staining on day 14 after the operation indicated that renal fibrosis was markedly reduced in the RBP-J cKO mice: the interstitial collagen area in the fibrotic kidney of the RBP-J cKO mice was about half of that in the control (Fig. 1A and 1B). The gene discussed is RBPJ; the disease is renal fibrosis.