Later, Lim et al. observed that the downregulation of MT2A expression in breast cancer cells could induce cell cycle arrest at the G1 phase to inhibit cancer cell growth, and the underlying molecular mechanisms involved the regulation of cell cycle-related genes including ataxia telangiectasia mutated (ATM) and cell division cycle 25A (cdc25A) [39]. The gene discussed is ATM; the disease is cancer.