CXCR4 and hepatocellular carcinoma: Both studies of celastrol-treated cancer explored HCC via the expression of CXCR4, p53 activation, and MMP expression, specifically MMP-2 and MMP-9. Celastrol was found to reduce the expression of CXCR4, which caused the downstream pathway PI3K/Akt to be reduced as CXCR4, which acted as a precursor to the pathway.