Since IFNγ upregulates PD-L1 expression by melanoma cell lines, [45] (Additional file 3: Figure S3 a,b) we assessed whether concomitant treatment of melanoma cells with IFNγ and PD-1 inhibitory antibody resulted in further enhancement of T-lymphocyte lysis by T-lymphocyte clones specific for the IP processed the NY-ESO-192–100 epitope (Additional file 3: Figure S3c, d). Here, PDCD1 is linked to melanoma.