Although specific data for EGFR and HER2/neu receptor-mediated endocytosis in populations of mammary adenocarcinoma (SKBr-3) is somewhat limited, other neoplastic cell types like metastatic multiple myeloma are known to internalize and metabolize approximately 8 × 106 molecules of anti-CD74 monoclonal antibody per day [70]. This evidence concerns the gene ERBB2 and breast adenocarcinoma.