CTRL and Splenomegaly: Survival was similar between Ctrl+Hoxa9 and cKO+Hoxa9 groups in primary recipients transplanted with multiple doses (400 K, 100 K, or 30 K cells) (Fig. 1E), with similar degrees of leukemic infiltrate (Fig. S3A–F) and splenomegaly at morbidity (Fig. S3G).