PECAM1 and neoplasm: To further examine which cell types expressed FGF2 and FGFR2 in tumor microenvironments, we isolated CD31+ cells (as endothelial cells), Thy-1–positive (Thy-1+) cells (as pericytes), and CD45-positive (CD45+) cells (as tumor-infiltrating lymphocytes) that are major components in tumor stroma cells by using microbeads coated with each respective Ab.