Indeed, in a recent study [41] on archival colorectal cancer specimens using fluorescent immunohistochemistry approaches, the architectural expression (tumor, stroma, and vessel) of endosialin, ECM components (fibronectin, collagens types I and IV), PDGFR-β, HIF-2, and CAIX demonstrated a complex interplay between endosialin and the tumor microenvironment. The gene discussed is CA9; the disease is colorectal cancer.