Besides these commonalities between both IBD patient cohorts, UC and CD patients also featured several entity‐specific differences in their LPMC composition: The colonic LP of UC patients, but not that of CD patients, was infiltrated with PD‐1+CD4+ and PD‐1+CD8+ effector T cells, which points to a chronic activation of these T cells, potentially due to translocation of intestinal antigens into the LP. This evidence concerns the gene CD8A and inflammatory bowel disease.