To test the effect of EGCG on IFN-γ-induced PD-L1/PD-L2 expression, we treated three human metastatic melanoma cell lines (1205Lu, A375 and HS294T) with either EGCG (10 μM), IFN-γ (10 ng/mL) or a combination of both for 24 h and analyzed the cell surface expression of PD-L1 and PD-L2. Here, PDCD1LG2 is linked to metastatic melanoma.