Tumor necrosis factor superfamily/tumor necrosis factor receptor superfamily (TNFSF/TNFRSF) proteins are expressed in immune cells, and are frequently activated or dysregulated in inflammatory diseases such as inflammatory bowel disease (IBD; De Voogd et al., 2016), systemic lupus erythematosus (SLE; Jackson and Davidson, 2019), rheumatoid arthritis (RA; Croft and Siegel, 2017), Crohn’s disease (CD; Hong et al., 2016), and hepatitis (Shin et al., 2016). The gene discussed is TNF; the disease is rheumatoid arthritis.