Electrical stimulation of the splenic plexus, in rats, has been shown to reduce levels of systemic tumor necrosis factor (TNF) after administration of the endotoxin lipopolysaccharide (Kees et al., 2003; Vida et al., 2011) and mitigated clinical symptoms in a mouse model of rheumatoid arthritis (Guyot et al., 2019). This evidence concerns the gene TNF and rheumatoid arthritis.