Subcutaneous injection using HCC‐patient‐derived xenografts (PDXs) was shown to express FGFR4 and resulted in an increase of circulating sEV–vWF in mice (Figure9A; Figure S8A, Supporting Information), revealing that this is a relevant mouse model to examine the therapeutic efficacy of anti‐vWF antibody, the pan‐FGFR inhibitor erdafitinib, and sorafenib (Figure 9B). This evidence concerns the gene FGFR4 and hepatocellular carcinoma.