CD4 and melanoma: Cell typing based on established blood cell type gene expression signatures (mapped from human genes to dog orthologs) for Melanoma PBMCs identified an average of 51.3% T cells (41.1 to 60.3%), 23.5% CD4 + T cells (19.3 to 26.6%), 27.8% CD8 + T cells (21.8 to 33.7%), 29.6% monocytes (23.6 to 35.6%), 12.0% B cells (4.6 to 21.0%), 2.3% erythroid cells (0.4 to 4.3%), 1.6% dendritic cells (0.1 to 3.2%), 0.6% NK cells (0.3 to 1.2%), 0.7% megakaryocyte cells (0.2 to 1.4%) and less than 1% maximum for any other cell type (Fig. 6b; Supplementary Table 6).