CUBN and Miyoshi myopathy: However, working with purified monoclonal Igs allowed us to distinguish between patients with clonal or non-clonal GlcSph-reactive Ig(s), and we show that GlcSph is targeted by the patient’s clonal Ig in 16% of MGUS and MM cases with GlcSph-reactive Igs, or about half the fraction (33%) reported by Nair et al., whose studies did not separate clonal from non-clonal Igs [8].