In addition, compared to thiopurine monotherapy, anti-TNF monotherapy was associated with an increased risk of serious infection (HR 1.71; 95% CI 1.56–1.88) but on the other hand with a decreased risk of opportunistic viral infection (HR 0.57; 95% CI 0.38–0.87), which shows the heterogeneity of findings [82]. The gene discussed is TNF; the disease is infection.