For instance, circ-SERPINE2 promotes the development of GC (Liu et al., 2019); hsa_circ_0000520 acts as a patent biomarker for GC and is involved in GC tumorigenesis (Sun et al., 2018); and cirMC3 increases the progression of GC by sponging miRNA-296-5p with PTEN (Rong et al., 2019). This evidence concerns the gene PTEN and gastric cancer.