CD44 and hepatocellular carcinoma: RAB27A/B, CD44, CDC42, and CLND3 are among the HCC exosomal proteins that are involved in carcinogenesis and metastasis [10], while the S100 calcium binding protein A4 (S100A4), caveolin-1 (CAV1), and CAV2 are enriched in metastatic HCC-derived exosomes both in mRNA and protein forms [10,11].