For example, higher levels of pro-inflammatory cytokines (e.g., IL1B, IL6) were detected in macrophages derived from co-cultures with fibroblasts, in line with transcriptomic evidence from recent IBD studies, implicating macrophage and fibroblast communication in drug unresponsiveness in adult patients with ulcerative colitis (UC)7 and ileal Crohn’s disease CD8, where several receptor-ligand pairs mediating interactions between fibroblasts and macrophages were highlighted, including IL1A, IL1B, and TNF produced by macrophages8. Here, IL6 is linked to ulcerative colitis.