… it is important to humanize these antibodies for human therapeutic purposes without impacting their binding affinity towards antigen targets.— Vinh Dang et al., Clinical and Developmental Immunology Dr. Joe Conner, a scientist with Viragen who conducted the experiments, explained that "humanizing an antibody requires removing most of the non-human regions of the protein by genetic engineering and replacing them with equivalent human components."— Anthony J. Brown, Reuters Health Medical News Trastuzumab is a humanized monoclonal antibody whose antigen-binding domain Fab recognizes a tyrosine kinase receptor … that is overexpressed in some breast cancers, and its anticancer activity is thought to involve disruption of cell proliferation signaling through this receptor. — Science