The authors showed that CXCR4 is an essential contributor to CD90+ mediated distant metastasis, as only CD90+CXCR4+ HCC cells developed metastases in NOD/SCID mice, whereas CD90−CXCR4−, CD90−CXCR4+ and CD90+CXCR4− cells failed to do so [179]. This evidence concerns the gene CXCR4 and hepatocellular carcinoma.