NOTCH4 and systemic lupus erythematosus: Pathway analysis results revealed that SLE-associated variants were highly enriched in the regulation of interferon signaling, PD-1 signaling, MHC-class II antigen presentation, TCR/BCR signaling, cytokine signaling, TNF signaling, NOTCH4 signaling, calcium-activated potassium channels, and cell-cell junction organization pathways.