Flow cytometry of lymphoma cells. (A) Unfractionated splenocytes from mice diagnosed with splenic lymphoma and peripheral leukemia (lymphoma) were stained for various markers of B-cell differentiation and activation and compared with asymptomatic non-Tg littermate splenocytes (control). Numbers in each square refer to percentages of gated events in a particular quadrant. (B) Peritoneal lymphocytes of premalignant, asymptomatic Tg mice (asymptomatic) were compared with age-matched littermate (control) to assess expansion of the B-1 cell population in the peritoneum.