PTGDR and Bloom syndrome: To confirm the involvement of Gas6/Axl signaling pathways in mediating the inhibitory effects on BLM-induced EMT and fibroblast activation, the Axl selective inhibitor BGB324, the COX-2 inhibitor NS-398, and PGE2 and PGD2 receptor antagonists, including EP2/EP4 (AH-6809) and DP2 (BAY-u3405) antagonists, were co-administered with rGas6 1 day before BLM treatment and then administered once/day (AH-6809) or once every 2 days (BGB324, NS398, and BAY-u3405) for 2 weeks after BLM treatment.