In this study, we demonstrated that CD8 T cells displayed close interaction with endothelial cells (EC) via the Fas ligand (Fasl)-Fas signaling pathway, leading to the apoptosis of EC and rarefaction of peritubular capillaries (PTCs) and renal fibrosis, which was largely reversed by the elimination of the CD8 T cells. The gene discussed is FASLG; the disease is renal fibrosis.