Thus, we may have underestimated the number of pauci-symptomatic infections if they were contracted early during the follow-up, particularly for patients treated with anti-TNF, that can attenuate seroprevalence as suggested in some studies (43, 44), even though another study recently showed that patients with IBD previously infected with COVID-19 have similar quantitative antibody response as healthy controls previously infected with COVID-19 (45). This evidence concerns the gene TNF and inflammatory bowel disease.