“…Upon interaction with cell-specific markers, antibodies can show direct cytotoxic effects by several mechanisms of action, e.g. blocking of growth factor receptors (Baselga and Mendelsohn, 1994), induction of apoptosis (Trauth et al, 1989), and formation of anti-idiotypic antibodies (Fagerberg et al, 1994), or indirect effects, such as antibody-dependent cellular cytotoxicity (ADCC) (Steplewski et al, 1983) and complement-mediated cytotoxicity (Ballare et al, 1995). As the cytotoxic actions induced by antibodies often are insufficient, they have been coupled to various toxic substances, including radioactive isotopes (Wilder et al, 1996), toxins (Kreitman, 1999) and chemotherapeutic drugs (Garnett et al, 1985), to enhance their potency.…”