['The purpose of this study was to investigate the potential role of nectin-4 in systemic lupus erythematous (SLE) cell apoptosis during the disease development and its potential mechanism.', 'Human peripheral blood mononuclear cells (PBMCs) were obtained for the isolation of monocytes and T lymphocytes. siRNA-nectin-4 plasma was constructed for the transfection into T cells using Lipofectamine 2000 reagent. siRNA with no nectin-4 sequence was transfected into T cells for the control group. mRNA expression of nectin-4 in cells was analyzed using RT-PCR method. Effect of netin-4 expression on T cell apoptosis was analyzed with Annexin V-FITC cell apoptosis kit. Moreover, effects of nectin-4 expression on cell apoptotic-related proteins expressions were detected using western blotting analysis.', 'Nectin-4 was significantly overexpressed in cells from SLE group compared with healthy control (HC) group (P<0.05). When T cells were transfected with sinectin-4, nectin-4 slicing increased cell apoptosis in HC group but significantly decreased apoptosis in SLE group (P<0.05). Nectin-4 slicing significantly decreased CD40L and CD17 expressions in SLE (P<0.05), but performed no effect on CD11a expression. Moreover, nectin-4 down-regulation could significantly decrease Bcl-2, Bcl-XL, and caspase-6 expressions but increase Bax level in SLE group.'] Does down-regulation of nectin-4 inhibit apoptosis in systemic lupus erythematous ( SLE ) through targeting Bcl-2/Bax pathway?