HMGA2 and neoplasm: The oncogenic function of Lin28B is primarily attributable to its repression of let-7 biogenesis, reflecting the fact that let-7 miRNAs exert their tumor-suppressive functions by negatively regulating the expression of essential oncogenes, such as HMGA2, Myc and Ras, which modulate cell proliferation [8, 9, 11, 32].