Furthermore, olaparib maintenance therapy can significantly inhibit the IL‐6 and TNF‐α level, and increase IFN‐γ level, the proportion of CD4+ T cells, and the CD4+/CD8+ ratio, indicating that olaparib maintenance therapy has a significant therapeutic effect on recurrent ovarian cancer and can be used as the preferred treatment for patients with recurrent ovarian cancer. This evidence concerns the gene IFNG and ovarian cancer.