HOXB8 and leukemia: Hoxb8-FL cell–derived leukemia was almost fully penetrant in Cdkn2a-WT MYB::PLEKHO1, Cdkn2a-KO MYB-TR, and Cdkn2a-KO MYB::PLEKHO1 recipient mice but was rarely observed in other genotypes and only with significantly longer latency (Figure 4D).