1. Clinicopathologic and Prognostic Implications of Programmed Death Ligand 1 Expression in Thymoma 
Shintaro Yokoyama, MD, Hiroaki Miyoshi, MD, PhD, Tatsuya Nishi, MD, Toshihiro Hashiguchi, MD, Masahiro Mitsuoka, MD, PhD, Shinzo Takamori, MD, PhD, Yoshito Akagi, MD, PhD, Tatsuyuki Kakuma, PhD, Koichi Ohshima, MD, PhD 
The Annals of Thoracic Surgery 
Volume 101, Issue 4, Pages (April 2016)
DOI: /j.athoracsur
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

2. Fig 1
Definition of the programmed death ligand 1 (PD-L1)–positive rate. The number of pixels of the PD-L1–positive area (upper row, right column, stained in black, ×200) was divided by that of the cytokeratin-positive area (lower row, right column, stained in black, ×200) to calculate the PD-L1–positive rate. It was calculated to be 73% in this sample obtained from a patient with type B1 thymoma (value of the PD-L1–positive area, 397,694 pixels/value of the cytokeratin-positive area, 544,512 pixels).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

3. Fig 2
A receiver operating characteristic curve, with the optimal cutoff point for the PD-L1–positive rate indicated as 38% by Youden’s index (arrow).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

4. Fig 3
Immunohistochemical analysis of cytokeratin and programmed death ligand 1 (PD-L1) expression in thymoma. PD-L1 was stained in the cytoplasm or cell membrane (right column, ×200) of epithelial tumor cells, and the staining pattern was identical to that of cytokeratin (left column, ×200). Infiltrating lymphocytes did not demonstrate PD-L1 expression (inset in the right column, ×600).
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

5. Fig 4
Disease-free survival and overall survival curves. (A) Patients with high programmed death ligand 1 (PD-L1) expression (solid line) showed significantly worse disease-free survival compared with those with low expression (dotted line). (B) Overall survival curves for patients with low PD-L1 expression (dotted line) and high PD-L1 expression (solid line) after complete resection showed no significant differences.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions

6. Fig 5
Disease-free survival curves stratified by Masaoka stage and World Health Organization classification between high and low programmed death ligand 1 (PD-L1) expression (solid lines, high PD-L1 expression; dotted lines, low PD-L1 expression, respectively). (A) Disease-free survival curves between high and low PD-L1 expression in Masaoka stage I/II cases. (B) Disease-free survival curves between high and low PD-L1 expression in Masaoka stage III cases. (C) Disease-free survival curves between high and low PD-L1 expression in type A/AB/B1 cases. (D) Disease-free survival curves between high and low PD-L1 expression in type B2/B3 cases. Patients with high PD-L1 expression revealed a tendency to have worse disease-free survival compared with those with low PD-L1 expression in all analyses, although significant differences were not observed.
The Annals of Thoracic Surgery  , DOI: ( /j.athoracsur )
Copyright © 2016 The Society of Thoracic Surgeons Terms and Conditions