It is important therefore to establish in future studies whether there is any correlation between the enzymatic activity of sCD73 in the peripheral blood of patients with advanced melanoma and clinical outcomes following PD-1 blockade regardless the treatment; or whether sCD73 enzyme activity in the serum could change after receiving PD1 blocking antibodies and if this value could be still associated with response rate (regardless the changes of CD73). Here, NT5E is linked to melanoma.