HDAC9 and B-cell non-Hodgkin lymphoma: In this study, we found that c-Myc, miR-21 and Mxd1 form a positive-feedback loop, which is pro-survival for B cell lymphoma; NL101, a DNA/HDAC dual-targeting small compound 18, 19, can effectively inhibit the growth of B cell lymphoma through blocking c-Myc/miR-21/Mxd1 loop.