HMGA2 and cancer: Cancer development, differentiation, and progression are all suppressed by let-7's ability to inhibit oncogenic proteins such as RAS (Wang et al. 2012a; Shell et al. 2007; Johnson et al. 2007a), HMGA2 (Johnson et al. 2007a; Lee and Dutta 2007; Peng et al. 2008; Yu et al. 2007; Mayr et al. 2007), c-Myc (Wang et al. 2012a; Shell et al. 2007; Johnson et al. 2007a), and cyclin-D2 (Wang et al. 2012a; Shell et al. 2007).