Fig 2: A heat map presenting data on 20 immune checkpoints from a TMA containing 124 GC patient samples.The abscissa represents the patient number of 124 patients in the TMA, and the ordinate represents the expression of LSECtin, VISTA, PD-L1, IDO, TIM-3, TNFRSF14, B7M4, CEACAM1, NECTIN2, CD44, CD155, ADENOSINE, TLR4, HMGB1, SIGLEC6, FAS-L, SIGLEC15, CD73, Galectin-9 and PD-L2.

Fig 3: Reversal of EMT returns immune checkpoint expression to control levels in Hep3B cells. Fluorescence microscopy showed (A) higher expression of PD-L1 upon EMT induction and lower expression of PD-L1 following reversal assay and (B) higher expression of CD73 upon EMT induction and lower expression of CD73 following reversal assay in Hep3B cells. Scale bar, 100 µm. Magnification, ×40. (C) Western blot analysis demonstrated higher expression of PD-L1, CD73, B7-H3 and PD-L2 upon EMT induction and lower expression following reversal assay in Hep3B cells. n=3. *P<0.05, **P<0.01. GAPDH was used as the loading control. EMT, epithelial-to-mesenchymal transition; TNF-α, tumor necrosis factor-α; MET, mesenchymal-to-epithelial transition; PD-L, programmed death receptor ligand.

Fig 4: Patients with rheumatoid arthritis with diffuse large B-cell lymphoma stained with PD-1, PD-L1/PAX5 and PD-L2/PAX5 (antibody NAT105/ab52587 (Abcam, Cambridge, UK) for PD-1, antibody E1L3N/13684 (Cell Signaling Technology, Danvers, MA, USA) for PD-L1, antibody D7U8C/82723 (Cell Signaling Technology) for PD-L2 and antibody M7307/DAK-Pax5 (Dako, Santa Clara, CA, USA) for PAX5). (A): High amounts of PD-L1+ tumor cells and TILs. (B): A high amount of PD-L1+ TILs and a low amount of PD-L1+ tumor cells. (C): Low amounts of PD-L1+ tumor cells and TILs. (D): High amounts of PD-L2+ tumor cells and TILs. (E): A high amount of PD-L2+ TILs and a low amount of PD-L2+ tumor cells. (F): Low amounts of PD-L2+ tumor cells and TILs. (G): A high amount of PD-1+ TILs and no PD-1+ tumor cells. (H): PD-1+ tumor cells and a few scattered PD-1+ TILs. Magnification: 400× in all images. Legends: PD-1+/PD-L1+/PD-L2+ tumor cells = black arrow, PD-1+/PD-L1+/PD-L2+ TILs = black arrowhead, PD-1-/PD-L1-/PD-L2- tumor cells = green arrow, PD-1-/PD-L1-/PD-L2- TILs = green arrowhead.

Fig 5: Reversal of EMT returns immune checkpoint expression to control levels in hepatocellular carcinoma cells. Reverse transcription-quantitative PCR analysis demonstrated (A) lower expression of immune checkpoint molecules PD-L1, PD-L2, CD73 and B7-H3 in EMT induced Hep3B cells and (B) lower expression of immune checkpoint molecules PD-L1, CD73 and B7-H3 in EMT induced PLC/PRF/5 cells following reversal assay. n=3. *P<0.05, **P<0.01, ***P<0.005, ****P<0.001. EMT, epithelial-to-mesenchymal transition; TNF-α, tumor necrosis factor-α; MET, mesenchymal-to-epithelial transition; PD-L, programmed death receptor ligand.