Previous studies have reported serum inflammatory biomarkers of sciatica, and these include TNF-α, IL-4, IL-6, IL-8, IL-10, IL-17, IL-21, T helper lymphocytes 17, phospholipase A2, C-reactive protein, C-X3-C motif ligand 1, C-C motif ligand 2 and mast cell proteinase-1 [14–22]. The gene discussed is IL21; the disease is Sciatica.