CTLA4 and metastatic neoplasm: IHC results showed that among TIM-3, PD-1, LAG-3, cytotoxic T-lymphocyte antigen 4 (CTLA-4), T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT), and V-domain Ig suppressor of T cell activation (VISTA), TIM-3, PD-1, LAG-3, and VISTA were highly expressed in the stroma regions of primary or metastatic tumors of HGSOC patients, compared with normal ovarian tissues, with no noticeable difference observed in tumors in situ or metastasis (Fig. 6A and Supplementary Fig. 7B).