ERBB2 and melanoma: Treatment of eight melanoma cells in our study with Herceptin® did not affect the growth rate as determined by CCK-8 assay (data not shown), which were probably due to the relatively weak expression of HER2 in melanoma and the absence of FcR+ cells in vitro, for that FcR+ cells were shown to be essential for mediating the therapeutic effects of HER2/neu antibody [34].