In addition, p21/cip1 and p27/kip1 were important regulators of the cell cycle, while berberine could upregulate levels of p21/cip1 and p27/kip1, as well as increase their nuclear localization and post-translational protein stability via downregulating Akt, and then elevate cell cycle arrest and induce breast cancer cell apoptosis [37]. Here, AKT1 is linked to breast cancer.