The results in this study revealed that silencing TMEFF1 reversed the promotion effect of MIR503HG knockdown on cell proliferation, invasion, and EMT progress, as well as the inhibitory effect of MIR503HG knockdown on cell apoptosis, indicating that TMEFF1 acted as an oncogene in ovarian cancer, which was consistent with the previous reports. Here, TMEFF1 is linked to ovarian cancer.