ERBB2 and breast cancer: Recently, we developed an antibody-guided diiodinated heptamethine cyanine-based 2ICy7–Ab conjugate, where the antibody (Ab) is trastuzumab, and demonstrated the high efficiency of this conjugate in the PDT of human epidermal growth factor receptor 2-positive (HER2+) human breast cancer in a xenograft mouse model [41].