HMGA2 and hepatocellular carcinoma: CCAT1 promoted the proliferation and migration of HCC cells by functioning as a molecular sponge for miRNA let-7, and led to the control of endogenous targets, such as high-mobility group protein A2 (HMGA2) and c-Myc, suggesting that CCAT1 played a critical role in the growth and progression of HCC via competitively sponging to let-7 (11).