ERBB2 and cancer: In vitro, NB-PDT has been reported to be a very specific, selective, and potent approach to kill cancer cells expressing a variety of membrane receptors, such as epidermal growth factor receptor (EGFR) [7,8], human epidermal growth factor receptor 2 (HER2) [12], hepatocyte growth factor receptor (c-Met) [13], and G protein- coupled receptor (GPCR) [14].