It was recently shown that LPA enhances the intestinal epithelial barrier function and susceptibility to dextran sodium sulfate–induced colitis through LPAR1 in mouse colon (47); that LPA attenuates radiation-induced disruption of the AJC and mucosal barrier through LPAR2 in mouse colon (48); and that LPA induces the clustering of neuroblastoma cells overexpressing LPAR4 (49). The gene discussed is LPAR4; the disease is colitis.