Overexpression of CD39 has been observed in many human cancer types such as melanoma,[17] leukemia,[18] pancreatic cancer,[19] colon cancer,[20] and ovarian cancer.[21] Lower levels of CD39 mRNA in colorectal cancer appear to be associated with longer survival and could be linked to less invasive tumors.[20] Nevertheless, to date, there has been no comprehensive description of the levels of CD39 expression in tissue samples of human HCC collected from a representative and appropriately large cohort of patients, and its prognostic role has not been described. This evidence concerns the gene ENTPD1 and melanoma.