In SCLC and bladder cancer, the RB1-E2F1 signaling pathway upregulated the expression of EZH2 by binding to the promoter region of EZH2. Our results confirmed that E2F1 upregulated the expression of RACGAP1 in PCa, and RACGAP1 promoted the stability of EZH2 protein, which plays a synergistic role with E2F1 in promoting the expression of EZH2, consistent with the biological characteristics of the tumor. Here, RACGAP1 is linked to small cell lung carcinoma.