To confirm these results, we analyzed a publicly available CyTOF dataset (32) and found that CTLA-4 protein levels were reduced in circulating immune cells (CD45+), CD4+ T cells, and Treg cells (CD4+CD25+CD127-) in metastatic melanoma patients compared to healthy donors (Figures 8A–C). Here, PTPRC is linked to metastatic melanoma.