AFF4 and cancer: Such PPI inhibition resulted in significant reduction of DOT1L and its products H3K79me1/2, ENL and AFF4 in MLL-r leukemia cells (Figure 3B/C), which suppressed malignant gene expression related to MLL-AF9, DOT1L, HoxA9 and Myc (Figure 4), causing differentiation, apoptosis and inhibited proliferation of MLL-r leukemia and, more broadly, Myc-driven cancer cells.