Significantly, our studies revealed two breakpoints in the miR-2909-KLF4 axis caused by mutation in the 3′UTR-KLF4 and the altered Zf3 motif sequence, leading to loss of miR-2909 binding to the KLF4 3′UTR and loss of KLF4 binding to DNA sequences in target genes in T-cell ALL subjects. Here, KLF4 is linked to T-cell acute lymphoblastic leukemia.