Expression of downstream interferon-γ targets in melanoma cells. (A) Heatmap showing cell surface expression [relative mean fluorescence intensity (MFI); mean of two to five independent experiments] of HLA-ABC, HLA-DR, nerve growth factor receptor (NGFR), PD-L1, and PD-L2 in 39 melanoma cell lines with defined oncogenic drivers including 11 BRAFV600-mutant, 10 NRAS-mutant, 10 BRAF/NRAS wild type (BRAF/NRASWT), and 8 GNAQ/11-mutant uveal melanoma cell lines. Relative MFI < 1.5 is indicated by the arrow on the color bar. (B) Cell surface baseline expression (relative MFI) of HLA-ABC, HLA-DR, NGFR, PD-L1, and PD-L2 in a panel of 39 melanoma cell lines. Each dot represents one cell line and the median expression is indicated by the horizontal line. Low cell surface expression of HLA-ABC on the MP46 and SMU15-0217 cell lines is indicated. (C) Correlation matrix showing Spearman’s rank correlation analysis between cell surface expression of markers, as indicated. Spearman’s rank correlation values are shown within the similarity matrix. (D) Correlation matrix showing Spearman’s rank correlation analysis between transcript levels of HLA-A, HLA-DRA, NGFR, PD-L1, and PD-L2 (The Cancer Genome Atlas (TCGA) skin cutaneous melanoma (SKCM) dataset). Spearman’s rank correlation is shown within the similarity matrix. (E) Correlation between PD-L2 and HLA-DR cell surface expression and (F) mRNA transcript expression (TCGA SKCM dataset). Spearman’s rank correlation coefficient and p values are shown.