In some experiments, melanoma cells were pre-treated with kuromanin (inhibitor of CD38), dipyridamole (inhibitor of nucleoside transporter), α-β-methyl ADP (inhibitor of CD73) and β-γ-methyl ATP (inhibitor of CD203a/PC-1), to assess the individual contribution of each ectoenzyme in inhibiting T cell proliferation. Here, NT5E is linked to melanoma.