a, Survival curve for mouse littermate pairs. Inset: representative spleens from mice at postnatal day 60 (P60). Mut, mutant; WT, wild type. b, Progressive alterations in PB: 30 littermate pairs (W, wild-type; M, mutant) per time point. Bars show the data range; points show averages. WBC, white blood cells. c, Identification of blast population by CD45/SSC plot in BM and spleen. The blasts were sorted for Giemsa–Wright staining, PCR genotyping and lineage analyses. Δex5, exon-5-deleted Pten allele.