Mechanistically, our experiments suggested thatRP1 interacted with the complex p-4E-BP1/eIF4Eto attenuate p27kip1 translation, and therefore promote breast cancer progression.Moreover, we demonstrated that KLF5 recruits p300 to the RP1 promoter to positively regulate RP1 transcription, and a positive correlation between KLF5 andRP1 was found in breast cancer. The gene discussed is EP300; the disease is breast cancer.