Credit: CC0 Public Domain

Oral contraceptives are implicated in slightly increasing breast cancer risk. This birth control method contains forms of estrogen, a hormone that binds ERalpha (estrogen receptor alpha), to alter the reproductive cycle. While much is known about estrogen signaling, few have researched how receptor homeostasis is maintained to ensure regular cycling.

Deborah Lannigan, Ph.D., and colleagues discovered that RSK2, a potential tumor-suppressor protein, is integral for ERalpha levels when comparing reproductive tissues of wild-type and RSK2 knockout mice.

Further analysis by mammary gland staining showed that RSK2 maintains receptor homeostasis, and therefore regular cycling, by reducing oxidative