Analysis of dysgammaglobulinemia in B/WcKO mice. Serum from 6- to 8-week-old (A) or 6-month-old (B) naive WT, B/WcKO, and WKO mice was tested for total serum IgM, IgG, IgA, and IgE concentrations by ELISA. Values of individual mice are shown. Bars indicate mean ± SEM. Significance was assessed with the Student t test. *P < .05, ***P < .001, and ****P < .0001.