To delineate the discrepant stroma characteristics between WPOI 1–3 and WPOI 4–5, we evaluated the staining intensity for several stromal components, including CD4+ T cells, CD8+ T cells, Foxp3+ Tregs, CD68+ tumor-associated macrophages (TAM), CD31+ endothelial cells, CD146+ pericytes, and Collagen I+ stromal cells (Fig. 2a). The gene discussed is PECAM1; the disease is neoplasm.