Mesenchymal cells were identified by lack of endothelial (Pecam1, encoding for CD31) and hematopoietic (Ptprc, encoding for CD45) cell markers, and by expression of mesenchymal genes such as Thy1 and Fap. Expression of Pdpn was used to further distinguish between CAFs (Fap+Pdpn+) and cancer-associated pericytes (CAPs, Fap+Pdpn-), as previously described44. Here, PECAM1 is linked to cancer.