KLF4 and acute lymphoblastic leukemia: Since KLF4 represses the Map2k7 gene, which encodes a dual specificity mitogen-activated protein kinase kinase 7 (MAP2K7), the epigenetic silencing of KLF4 in patients and its conditional deletion in the mouse model of T-ALL lead to the aberrant activation of the MAP2K7-JNK pathway (Figure 4B) (37, 77).