GJA4 and neoplasm: Our study further reveals that the lower density of the newly formed vessels lacking Cx37, which we observed within the three tumoral models studied (subcutaneous TC-1 cells, intravesical TC-1-luc cells, subcutaneous B16-F10 cells), was not associated to obvious changes in the structural and functional maturation of the growing vessels, as reflected by a control coverage by mural cells, a control permeability and control areas of tumoral hypoxia, respectively.