ATP8B1 and cholelithiasis: The serum bile acid profile of ICP4 group was different from normal pregnant group, ICP1 group, ICP2 group, ICP3 group, cholelithiasis group and hepatitis B virus group, and the serum concentrations of UDCA, GUDCA, TUDCA, GCA and GLCA in ICP4 group were significantly higher than normal pregnant group (P < 0.01) (see Fig. 1, Table 3).