PECAM1 and hepatocellular carcinoma: To confirm the purity of our isolated pericytes derived from normal adjacent tissues and tumors, we performed flow cytometry and immunostaining experiments with our isolated pericytes, indicating that the TPC and NPC derived from NSCLC or HCC patients expressed PDGFRβ and CD146 as well as newly identified pericyte markers desmin and CD13, but did not express endothelial cell marker CD31 and CD34, immune cell marker CD45, or fibroblast marker FAP (fibroblast associated protein) (Fig. 2a, b and Supplementary fig. 3a, b).