After surgery and without immunosuppression, despite normal absolute number of lymphocytes, the patient displayed a high CD4:CD8 ratio in peripheral blood when compared to age-matched VEO-IBD patients (Fig. 1c), a published age-matched reference population,23 adult and infant healthy controls, and adolescent PIBD with active disease (inflammation) or disease in remission (Fig. S1A). This evidence concerns the gene CD4 and inflammatory bowel disease.