PECAM1 and neoplasm: To further investigate this possibility, we performed a second experiment to enrich for the CAFs in the Ccne1+ immune-excluded model by FACS-sorting dsRED- CD45− CD31− CD90+ (non-tumor, non-immune, non-endothelial) cells and analyzing the purified CAFs by scRNA-seq (Fig. 3c, d and Supplementary Fig. 3a).