Mice with floxed A20 (A20fl/fl) and floxed Abin-1 (Abin-1fl/fl) on a Vil-cre-ERT2+ background (A20/Abin-1T-ΔIEC) undergo acute deletion of A20 and Abin-1 in IECs upon treatment with tamoxifen, culminating in spontaneous apoptotic IEC death, severe enterocolitis, and rapid mouse lethality (9). The gene discussed is MAPK3; the disease is enterocolitis.