CCND1 and gastric cancer: A summary of recent studies has found that in esophageal squamous cell carcinoma (ESCC), colorectal cancer (CRC), lung cancer (LC), three negative breast cancer (TNBC), prostate cancer (PCa), hepatocellular carcinoma (HCC) and gastric cancer (GC), circ-ITCH could up-regulate the expression of linear ITCH via sponging miR-7, miR-17 and miR-20a, thereby inhibiting the canonical Wnt pathway and further suppressing the activation of c-Myc and cyclinD1 (Wan et al., 2016; Wang S. et al., 2019; Li S. et al., 2020; Peng and Wang, 2020; Yang et al., 2020).