CD34 and neoplasm: The immunohistochemical staining of the same specimens as those used in the present study revealed that the number of CD34-positive endothelial cells in the tumor tissues was significantly correlated with poor clinical outcomes of the OSCC patients; however, there was no significant correlation between the CD34-positive cell number and IL-8 expression or CD163-positive M2 macrophage-infiltration in the tumor tissues (authors’ personal communications).