ID1 and plasma cell myeloma: For example, in B cell lymphoma, anti-Id antibodies appear to be important for tumor eradication (Syrengelas and Levy, 1999), while in multiple myeloma, Id-specific T cells seems to be the therapeutically most important arm of Id-immunity (Lauritzsen et al., 1994; Dembic et al., 2000; Corthay et al., 2005; Haabeth et al., 2011).