IGF2 and neoplasm: (Fig. 4A–C) In addition, the mRNA expression of insulin-like growth factor 2 (IGF2), which is a marker of fibroids/tumour proliferation, and embryonic smooth muscle myosin heavy chain (SMemb), which is a marker of proliferating smooth muscle cells (SMCs), was significantly up-regulated in leiomyomas that were treated with GnRHa.