Expression of Ngb and Cygb in human astrocytomas. Tissue microarrays containing cores obtained from various human brain tumors were stained with to antibodies to Ngb or Cygb. Positive staining was visualized by the chromogenic reaction of HRP with DAB. Photomicrographs were obtained at 20× magnification, and the scale bar indicates 50 μM. Sections of representative examples of Grades I-IV astrocytoma are shown.