LYN and Splenomegaly: However, unlike in Lyn-/-IL-10-/- mice, there was no enhancement of splenomegaly, CD4+ T cell activation (as measured by CD69 expression), CD4 T cell naïve and effector memory frequencies, or myeloid expansion (Supplementary Figures 2B–D) in Lyn-/-.Ighg3-cre.DTA and Lyn-/-.Ighg3-cre.IRF4f/f mice compared to Lyn-/- controls.