CD34 and neoplasm: The less aggressive tumor cells were positive for CD34 and smooth muscle actin (SMA), with a Ki-67 index of 2% (Figures 1(f) and 1(g)), while the highly aggressive tumor cells were negative for CD34 and negative or weakly positive for SMA, with a Ki-67 index of 21% (Figures 1(f) and 1(h)).