Previous studies have shown that neoadjuvant chemotherapy can improve immune function and reduce the risk of recurrence.14 The results of this study showed that the levels of CD3+, CD4+, and CD4+/CD8+in both groups were significantly improved compared to before treatment (P<0.05), and the observation group showed more significant improvement than control group (P<0.05), indicating that the combination of PDS and neoadjuvant chemotherapy has a stronger effect on improving immune function indicators in ovarian cancer patients. Here, CD4 is linked to ovarian cancer.