HIPK3 and hepatocellular carcinoma: In recent studies, circular RNAs have been reported to participate into tumorigenesis of various types of tumours, including HCC.14, 15 For example, circular RNA SMARCA5 inhibited the proliferation and migration of HCC cells by sponging with miR‐17‐3p and miR‐181b‐5p.16 Moreover, circular RNA circMTO1 was found to function as the sponge of miR‐9, thereby suppressing HCC progression.17 Circular RNA HIPK3 regulated cell proliferation and migration by sponging miR‐124 to increase Aquaporin‐3(AQP3)expression.18 These studies suggested that circular RNA functioned as a miRNA sponge in HCC cells.