PECAM1 and metastatic melanoma: Similar to our benchmarking in breast cancers, we observed a strong conservation of the housekeeping gene ACTB and markers for cancer clusters (EPCAM in prostate and MITF in melanoma), immune subsets (PTPRC), endothelial cells (PECAM1/CD31) and fibroblast/perivascular (PDGFRB) cells in prostate cancers and the metastatic melanoma (Fig. 2d, e; Additional file 2: Figure S1f; Additional file 2: Figure S2d-f).