Notch inhibition decreases lymphoproliferation. CBA-lpr^cg mice were randomized to treatment with DAPT 5mg/kg per day versus vehicle control (6 treated, 9 control). After 6 weeks of treatment, a decrease in disease burden is visually apparent. Shown here are a control animal at (A) initiation and (B) after 42 days of vehicle, and a treated mouse at (C) initiation of DAPT treatment and (D) after 42 days of treatment. Serial ultrasounds were performed every 2 weeks to document lymph-node volume (mm³) and splenic area in (mm²). Treated mice showed a statistically significant (P = .009) decrease in lymph-node volume after 2 weeks of treatment compared with control mice (E). Treated mice also showed a statistically significant (P = .001) decrease in splenic area by 2 weeks of treatment compared with control mice (F). No statistical difference existed between groups at initiation of treatment. Bars represent mean lymph node volume (E) or splenic area (F) from mice at each time point, and error bars represent SEM.