Fig. 1.
Immunohistochemical analysis of human epidermal growth factor receptor 2 protein expression (×200). (A) Immunostaining shows no staining on tumor cell membrane. (B) Immunostaining shows positive reaction (1+). (C) Immunostaining shows positive reaction (2+). (D) Immunostaining shows positive reaction (3+) with complete or basolateral membraneous staining.