In order to gain insight in the potential underlying mechanism of the highly attenuated colitis in Trem1−/− x Rag2−/− mice, colonic lamina propria cells that were isolated from both groups of mice in the absence of an adoptive CD4+ T cell transfer (healthy colon) or 12–13 days post colitis induction were analysed by FACS. Here, CD4 is linked to colitis.