(a) Hierarchical clustering of human samples based on gene expression of highly expressed genes (>100 RPKM). Coloring indicates high-order clusters and the confidence in clusters are indicated with bootstrap values (percentage). Samples analyzed include human immune samples (Burkitt’s lymphoma cell lines BL41 and BJAB, and white blood cells and lymphnode samples) and cells from putative melanoma circulating tumor cells (CTC), primary melanocytes (PM), melanoma cell lines SKMEL5 (SKMEL) and UACC257 (UACC), prostate cancer cell lines (LNCaP, PC3), bladder cancer cell line (T24) and human embryonic stem cells (ESC). (b) Expression of melanocyte makers (PMEL, MITF, TYR, MLANA) and immune marker PTPRC in single-cell transcriptomes from (a) with Burkitt’s lymphoma cell lines BL41 and BJAB (BL). (c) Gene expression levels in CTCs for an unbiased set of 100 immune and melanoma markers. (d–f) Heatmaps showing relative expression of melanoma associated tumor antigens (d), up-regulated plasma-membrane proteins (e), and down-regulated plasma-membrane proteins (f) in single-cell transcriptomes as in (b) with the addition of more immune samples (W: white blood cells, L: lymphnode). (g) Number of reads from individual PMs and putative CTCs that support the reference (G) or risk (A) allele for the melanoma-associated SNP (rs1126809).