KLK4 and systemic lupus erythematosus: In T1 vs. C group, the most upregulated protein in Complement and coagulation cascade pathway was plasma kallikrein (KLKB1), while Immunoglobulin heavy variable 6-1 (IGHV6-1) was the most upregulated protein in the pathways of Systemic lupus erythematosus, primary immunodeficiency, amoebiasis, phagosome, Staphylococcus aureus infection, Fc gamma R-mediated phagocytosis, Fc epsilon RI signaling pathway, Dilated cardiomyopathy, and Hematopoietic cell lineage.