PECAM1 and neoplasm: In fact, a significant decrease in tumor vasculature (CD31+, p < 0.001), cancer-associated fibroblasts (SMA+, p < 0.001), tumor-promoting M2 macrophages (Arg1+, p < 0.001), and infiltrating immunosuppressive regulatory T (Treg) cells (Foxp3+, p = 0.003) was observed in allografts derived from Beclin1-knockdown cells (shBecn1#1), as shown by immunohistochemistry (IHC) (Supplementary Figure S2C,D).