PTGDR and colitis: To identify the cell types in which loss of DP1 function exaggerated the murine colitis, DP1Flox/Flox (DP1F/F) mice were crossed with Tie2Cre, VillinCre, LysMCre, or SM22Cre transgenic mice to generate vascular endothelial cell, colonic epithelial cell, macrophage, or smooth muscle cell‐specific DP1‐deficient mice, respectively (Fig 4C).