Study of the spatial organization and immuno profile of 15 tumor types, revealing infiltration of CD8+ cytotoxic T cells and CD68+ macrophages in ovarian serous carcinoma TME (24); spatial enrichment analysis revealed that tumors were immune mixed and compartmentalized with varying expression of PD1, PD-L1, and IDO on a cell-type and location-specific basis, where highly ordered structures with PD-L1 and IDO along the tumor-immune border served as a hallmark of tumor compartmentalization in a triple-negative breast cancer patients (25). Here, IDO1 is linked to ovarian serous carcinoma.