FOXD1 and lip and oral cavity carcinoma: To validate if the IFN-α and IFN-γ-related signaling pathways are activated after FOXD1 knockdown in oral cancer cells, we performed luciferase-based promoter activity assays using commercialized luciferase-containing vectors used for determining the activities of IFN-α and IFN-γ-related signaling pathways in HSC4 cells (Figure 5B,C).