Characterization of plasma cell tumor development in p80HT mice.(A) Serum protein electrophoresis showing the presence of M-protein (+) in serum samples from p80HT mice, which is seen as a dense band or peak (M-spike) within the γ globulin region of serum proteins on an agarose gel. A pool of serum samples from patients with hypergammaglobulinemia was used as positive control. The positions of albumin and different globulin components of the serum are indicated. (B) Flow cytometry analysis of CD138+ plasma cell content in bone marrow samples from the #6698 and #7453 p80HT mice and their WT littermates. The bone marrow plasma cell content in both p80HT mice was more than 10%, a key criterion of MM. (C) X-ray on femurs and tibias from a p80HT mouse and its WT littermate. The arrow points to an area of lytic bone lesion. (D) Bone density analysis showing a significant reduction in bone mineral density in p80HT mice compared to age- and sex-matched WT mice (n = 5 per genotype). Data were analyzed using two-tailed Student’s t-test with P values indicated.