Despite a difference in the use of each agent, there was no significant difference in the use of biological agents between the two groups (16.9 vs. 20.2%, P = 0.376); non-tumor necrosis factor (TNF) inhibitors were used more frequently in the RA-ILD group (10.8% vs. 4.4%, P = 0.005), whereas TNF-inhibitor use was more prevalent in the RA-non ILD group (6.1% vs. 15.9%, P = 0.003). The gene discussed is TNF; the disease is rheumatoid arthritis.