ERBB2 and breast cancer: In previous studies, we demonstrated that humanized immunodeficient NOG-hIL-4-Tg mice successfully support the engraftment of human B and T cells following PBMC transplantation (34), generated tumor antigen-specific IgG antibodies after peptide vaccination (14) and characterized HER2-specific humoral responses in breast cancer-derived lymphocytes (22, 31).