CUBN and systemic mastocytosis: These studies revealed that the peptide sequences PALTAVETG and PALTAAETG of the VP1 coat proteins of human polioviruses types 1 (PV1) and 3 (PV3) and coxsackieviruses B1 (CVB1) and B3 (CVB3), respectively, were novel targets of monoclonal Igs: these sequences were specifically recognized by 10 (6.5%) monoclonal Igs (all IgGs) from a cohort of 155 MGUS/SM and 3 (2.0%) monoclonal IgGs from a cohort of 147 MM.