It has been reported that artemisinin and its derivatives cause cell cycle arrest mainly in the G0/G1 phase through downregulation of cyclin E, cyclin D1, and cyclin-dependent kinases 2 and 4 in several tumor cell lines, including human breast cancer cells [20], gallbladder cancer cell lines [21], neuroblastoma [22], lung carcinoma cells (A549), and nonsmall lung cancer cells (H1299) [23]. This evidence concerns the gene CDK2 and breast cancer.