We also examined the potentialapplicability of this method to identify tumor-specific antibodies in othercancers using the mammary carcinoma cell line SK-BR-3, which highly expressesthe cell surface tumor-associated antigen HER2/neu[37].Trastuzumab (HerceptinTM), a humanized antibody specific forHER2/neu, was specifically detected compared to an equalamount of a control IgG employing our method (Figure 1, D). Here, ERBB2 is linked to breast carcinoma.