However, in several types of differentiated mesenchymal tumor, including lipomas [29,30], leiomyomata [8,31,32,33], pulmonary chondroid hamartomas [34,35], endometrial polyps [36], and soft tissue chondromas [37], certain genetic mechanisms enable its untimely re-expression, biologically termed HMGA2 misexpression. The gene discussed is HMGA2; the disease is lipoma.