Pedigree of a patient with MGUS with a P-7–specific IgM paraprotein carrying the pP-7. (A) The pedigree shows the family of a 77-year-old man with IgM-MGUS (I.1), having a P-7–reactive paraprotein and carrying the hyperphosphorylated state of this protein. (B) Immunostaining of lysate bands derived from whole peripheral blood lysates from family members carrying wild-type (I.2; III.1) and pP-7 (I.1; II.1; III.2) after IEF. The numbers indicate family members in different generations.