Because RUNX3 has the potential role in TGF-β signaling, and TGF-β generally induces cell cycle arrest at the G0/G1 phase by increasing the expression or activity of specific cyclin-dependent kinase inhibitors [21], [22], [23] and many other potential targets [24], the tumor suppressor activity of RUNX3 may be realized by inducing cell cycle arrest [25], [26]. This evidence concerns the gene TGFB1 and neoplasm.