As an important part of the adaptive system, the role of CD4+ T cells in IBD onset and development had been concerned and affirmed for a long time.44 To validate the speculation from our correlation analysis, we isolated CD4+ T cells from CD patients, UC patients, and healthy controls respectively, and found that CD4+ T cells from CD patients secreted the most abundant IL12p40 protein. The gene discussed is CD4; the disease is inflammatory bowel disease.