Epithelial-mesenchymal transition (EMT) plays pivotal roles in organ fibrosis including that of kidney [14, 15] . It has been reported that a large proportion of the interstitial fibroblasts in fibrotic kidneys originate from proximal tubular cells [16] . Therefore, it is important to identify the molecules involved in the induction and progression of EMT of RTECs. TGF-b 1 is up-regulated in the fibrotic kidney and is the main inducer of EMT of RTECs [17] [18] . In the present study, we investigated the roles of the interaction of LFA-1 on peripheral blood mononuclear cells (PBMCs) and ICAM-1 on RTECs after stimulation of TGF-b 1 on the EMT.