FOXO4 and leukemia: The expression levels of FOXA2, FOXC1, FOXD1, FOXE1, FOXF1, FOXF2, and FOXG1 were downregulated in all types of leukemia, while those of FOXJ2, FOXJ3, FOXM1, FOXN2, FOXN3, FOXO3, FOXO4, and FOXP3 were upregulated in at least four subtypes of leukemia (Figure 1A).