MRI49372 macrocytic anemia and splenomegaly. (A) Representative light microscopy image of Wright-Giemsa–stained WT thin smear. (B) Representative light microscopy image of Wright-Giemsa–stained Ampd3^T689A thin smear. (C) Representative spleens from WT, MRI49372/+, and MRI49372 mice. (D) Spleen index, calculated as spleen weight (g)/mouse weight (g) for WT (n = 7), MRI49372/+ (n = 8), and MRI49372 (n = 7). Black bars represent median. ***P < .001. P values calculated using the Student t test.