CHEK1 and hepatocellular carcinoma: Aberrant expression of miRNAs in HCC has been profiled in many studies.21, 22, 23 A few studies have shown that miR-497 may suppresses angiogenesis, metastasis, and proliferation in HCC.17, 18 In addition, miR-497 was found to target specific oncogenes such as VEGFA, IGF-1R, CHEK1, and Raf-1.17, 18, 24, 25, 26 Those studies all show that miR-497 may act as a tumor suppressor, and it has been well known that miRNAs would exhibit cell-type or tissue-specific actions in a context-dependent manner, which may explain the differences between those studies.