MYD88 and Autoimmunity: IgM plasma cell expansion is temporally and genetically separable from autoimmunity in Lyn−/− mice; this phenotype develops in mice as young as 7–10 weeks of age with 100% penetrance, is B-cell intrinsic, and is not dependent upon MyD88 expression (Hua et al., 2014; Infantino et al., 2014; Lamagna et al., 2014).