Indeed, numerous studies have confirmed this point.(Cui et al., 2018) For example, circ‐SMARCA5 (Li et al., 2019), circ‐PRMT5 (Chen et al., 2018), circ‐ADAMTS9 (Rong et al., 2018), circ‐ANKS1B (Zeng, Chen, et al., 2018; Zeng, He, et al., 2018), and circ‐SMAD7 (Zhang, Wang, Wang, et al., 2019; Zhang, Wang, Zhu, et al., 2019) were proved to be the diagnostic or prognostic biomarkers for hepatocellular carcinoma, bladder cancer, gastric cancer, breast cancer, and esophageal squamous cell carcinoma, respectively. Here, SMAD7 is linked to hepatocellular carcinoma.