To confirm the CXCR4 expression level in vivo, we performed IHC staining on HCC tissues and found that CXCR4 and EMT-related proteins were highly expressed in HCC tissues with high and medium stiffness background as compared with that of normal stiffness background (Figure 2C, Figure S1, Figure S2), which was consistent with the results in vitro. This evidence concerns the gene CXCR4 and hepatocellular carcinoma.