Given the multiple binding sites for let-7 in many chromosomal 3’ UTR loci, it is possible that HMGA2 is mis-expressed when the relative abundance of HMGA2 mRNA transcripts suffice to bind available let-7 and sustain HMGA2 re-expression in benign mesenchymal tumors. The gene discussed is HMGA2; the disease is mesenchymal cell neoplasm.