CALCA and metabolic dysfunction-associated steatohepatitis: On this basis, we proceeded to find that ONO-AE3-208, as an EP4 receptor antagonist of PGE2 inhibition, could improve the disturbance of hepatic lipid accumulation and KC polarization balance in mice to some extent, attenuate inflammatory injury, and ultimately rescue the HBx-associated NASH phenotype, suggesting for the first time that the EP4 receptor of PGE2 may become a potential target for intervention.