As a confirmed target gene of miR-21, PTEN is involved in the interaction between GAS5 and miR-21.GAS5 can counteract the reduction of PTEN by miR-21, and play a synergistic role in tumor-suppression with PTEN (Hu et al., 2016; Cao et al., 2017; Tao et al., 2017; Zeng et al., 2019; Zhu et al., 2019). This evidence concerns the gene GAS5 and neoplasm.