... Her3/erbB3, and Her4/erbB4).All share a common structure, with an extracellularligand-binding domain, a transmembrane domain, and an intracytoplas mic tyrosine kinase domain[3-5]. Ligandbinding to ... and Her3, using cut-offs of greater than or equal to +1 ( range 0 to +3)for membra-nous staining of Her2 and Her3, and greater than orequal to 3 (range 0 to 12) for cytoplasmic expression of Her3.Her2 ... 2 Representative images of immunohistochemistry for Her2 (a, membranous staining and Her3 (b, membranous andcytoplasmic staining, and c, predominant cytoplasmic staining) 400 × magnification.Takikita...