CD55 and osteosarcoma: Vaccination of colorectal (Robins et al., 1991; Ullenhag et al., 2006) and osteosarcoma (Pritchard-Jones et al., 2005; Ullenhag et al., 2008) patients with 105AD7 mAb in alum alone or with BCG in the first immunization (Ullenhag et al., 2006), either failed to induce an anti-anti-idiotypic antibody response (Robins et al., 1991; Ullenhag et al., 2006) or induced a weak response against CD55 (Pritchard-Jones et al., 2005), but it was able to activate both anti-Ab2 and anti-CD55 T cell responses (Ullenhag et al., 2006, 2008).