PECAM1 and neoplasm: Most of these cells were tumor epithelial cells, characterized by high expression of keratin 19 (KRT19) and low expression of PTPRC (CD45), PECAM1 (CD31), and PDGFRB, which are markers for immune/hematopoietic cells, endothelial cells, and stromal cells, respectively (34–36) (Supplemental Figure 1B).