Chromosome 5q deletions (del(5q)) are common in high-risk (HR) Myelodysplastic Syndrome (MDS) and Acute Myeloid Leukemia (AML); however, the gene regulatory networks that sustain these aggressive diseases are unknown. Reduced miR-146a expression in del(5q) HR-MDS/AML and miR-146a-/- hematopoietic stem/progenitor cells (HSPC) results in TRAF6/NF- activation. Increased survival and proliferation of HSPC from miR-146alow HR-MDS/AML is sustained by a neighboring haploid gene, SQSTM1 (p62), expressed from the intact 5q allele. Overexpression of p62 from the intact allele occurs through NF-B-dependent feedforward signaling mediated by miR-146a deficiency. p62 is necessary for TRAF6-mediated NF-B signaling, as disrupting the p62-TRAF6 signaling complex results in cell cycle arrest and apoptosis of MDS/AML cells. Thus, del(5q) HR-MDS/AML employs an intrachromosomal gene network involving loss of miR-146a and haploid overexpression of p62 via NF-B to sustain TRAF6/NF-B signaling for cell survival and proliferation. Interfering with the p62-TRAF6 signaling complex represents a therapeutic option in miR-146a-deficient and aggressive del(5q) MDS/AML.