Immunohistochemical analysis of beclin 1 expression in breast tissues. Photographs were taken at × 200 magnification. A brown color represents positive staining of beclin 1. Counterstaining of nuclei was performed with hematoxylin as a blue color. (A) Positive staining of beclin 1 in adjacent normal breast epithelial cells; (B) Positive staining of beclin 1 in a breast tumor; (C) Weak immunoreactivity of beclin 1 in a breast tumor; (D) Negative control of beclin 1 staining in a breast tumor.
Li et al. BMC Cancer 2010 10:98 doi:10.1186/1471-2407-10-98