IKBKG and fibrosis: EXT5 (13) and EXT9 (14) are both mainly antagonizing the 5-HT2BR (EXT5: Ki = 45 nM, IC50 = 82 nM in IP1 accumulation assay; EXT9: Ki = 26 nM, IC50 = 29 nM in IP1 accumulation assay), and also exhibit low to moderate binding affinities to the 5-HT2AR and the 5-HT2CR. As mentioned above (Section 2.2.2), EXT5 and EXT9 were utilized for investigating the role played by the 5-HT2BR in fibrosis [36].