Around 90% of DKO mice at 20 weeks of age were resistant to diarrhea and did not exhibit weight loss whereas only 30% of CKO mice were diarrhea free at the same age (Figure 4, F and G), further validating the pathogenic role of IL-21 in Blimp-1 deficiency–induced colitis. The gene discussed is PRDM1; the disease is colitis.