CD34 and neoplasm: In this study, we found spheroid cells not only formed xenograft tumors in vivo, histopathological studies have also found that some cells composing of tumor vessel lumen showed anti human CD34 positive, indicating these cells in the vessel wall of xenograft tumors were originated from the cells of human origin, not derived from host (murine) cells, which suggested that TICs might be the progenitor for tumor vasculature.