PRF1 and systemic lupus erythematosus: Nonetheless, there areremarkable similarities in upregulated gene expression between SLE CD4+ Tcells and lpr DN T cells, including ITGAL (CD11a),CD40LG (CD40-ligand), IFNG (IFN-γ),RFR1 (perforin), GADD45A, andCXCR3 (5), suggesting apossible common mechanism.