CXCR3 and systemic lupus erythematosus: In SLE, CD4+ T-cells exhibit hyperactivation with reduced activation thresholds (57), where pDC-derived IFN-I induces endothelial cell production of CXCR3 ligands (CXCL9), promoting CD4+CXCR3+ T-cell arterial infiltration (58).