Biopsy ulcers in Vil1-Grem1 animals wererapidly covered by WAE (Figure 6A), whereasepithelial Bmp4 expression inVil1-Cre;Rosa26Bmp4 micedelayed coverage by WAE and retarded closure (Figure 6B, Supplementary Figure 6B). Here, VIL1 is linked to ulcer disease.