AXIN2 and neoplasm: On further analyses of double in situ hybridization for both FGF19 and either AXIN2 or SOX4, FGF19-expressing cells comprised approximately 4% and 10% of AXIN2+ and SOX4+ cells, respectively, consistent with the fact that nearly all tumor cells were AXIN2+ while only a fraction of tumor cells were SOX4+ (Fig. 2g).