In addition, after inhibiting the expression of PVT1, the proliferation, migration and invasion of breast cancer cells were inhibited by affecting the expression of p21[17] that is not only the main molecule regulating cell cycle, but also cyclin-dependent kinase, and can inhibit the activity of cyclin kinase complex by binding to cyclin-dependent kinase complex to regulate G, restriction point and G1max S checkpoint. Here, PVT1 is linked to breast cancer.