Fig 1: Thyroxine (T4)-induced PD-L1 complexes with nuclear proteins. Oral cancer (A) OEC-M1 cells and (B) SCC-25 cells were seeded on a cover glass. Cells were starved for 48 h, fed hormone-stripped serum-containing medium, and then treated with T4 in the presence and absence of 40 µM S31-201 for another 24 h. Cells were fixed for confocal microscopic analysis of PD-L1 accumulation (green color) or P300 (red color). Nuclei were counterstained with DAPI (blue color). Red square is PD-L1 and P300 co-accumulation (white arrow.). Confocal microscopy was conducted as described.