For example, MED23 is selectively required for Ras-active lung cancer cells [30]; MED19 was found to promote tumorigenesis of lung cancer using a xenograft mouse model [31]; MED28 expression is positively associated with poor outcome in breast cancer patients [32]; and MED1 and MED24 were also reported to cooperatively contribute to the growth of breast cancer cells [33]. Here, MED1 is linked to breast cancer.