CD19 and lymphoma: Moreover, at sacrifice R26+/AIDCd19+/creUng-/- mice harboured a different pattern of B cell lymphomas by immunohistochemistry evaluation, with a smaller proportion of large-B cell (LB) lymphoma and a bigger proportion of small B cell (SB) lymphoma than R26+/+Cd19+/creUng-/- mice (Figs 4B, 4D, S3, S4 and S5; see Methods for details).