In the current study, to gain mechanistic insights of how PRR11 regulates the expression of PTTG1, we used ChIP-qPCR and Co-IP to prove that PRR11 was expressed in the nucleus and can interact with and be recruited by E2F1 to the E2F1 binding site (5′-TTTGGGGC-3′) of the PTTG1 promoter region (−256/−142), consequently stimulate the expression of PTTG1. This study provided new ideas for future exploration of the function of PRR11 in promoting tumor development. The gene discussed is E2F1; the disease is neoplasm.