IDO1 and ovarian carcinoma: We further verified these observations with multiple cell lines: SKOV3 cells, an ovarian cancer cell line that constitutively expresses IDO1 (Figure 3D), HT1080 cells, a human fibrosarcoma cell line frequently used in ferroptosis studies (Figure 3E) and PT45 cells, an aggressive pancreatic adenocarcinoma epithelial cell line (Figure 3F).