Ectopic expression of miR-142-3p in MLL-AF4+ cell lines supresses cell proliferation, induces apoptosis, and down-regulates multiple genes known to regulate self-renewal including MLL-AF4, HOXA9, HOXA7, and HOXA10. Thus, miR-142-3p likely functions as a tumor suppressor in MLL-AF4+ ALL (Dou et al., 2013). The gene discussed is AFF1; the disease is acute lymphoblastic leukemia.