On 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumors of A/J mice, GTE administration in drinking water reduced PD-L1 expression on tumor cells and tumor volume and, in co-cultures of B16F10 melanoma cells/tumor-specific T cells, EGCG reduced PD-L1 expression as well and maintained IL-2 transcription [119]. This evidence concerns the gene CD274 and melanoma.