HAVCR2 and systemic lupus erythematosus: Many recent publications have documented specific gene and/or protein as potential biomarker of lupus activity, including haptoglobin, alpha-1 anti-chymotrypsin, retinol binding protein, miR-21, miR-181a, miR-196a, human T cell immunoglobulin domain and mucin-3 (TIM-3), TIM-3 ligands, TNF-like weak inducer of apoptosis, CD72, programmed death ligand 1, ferritin, insulin-like growth factor binding protein 2, tumor necrosis factor receptor type II, homocysteine and B-lymphocyte stimulator [24–38].