The multiplex IHC is performed with Opal 7-Color Automation IHC Kit (Akoya Bioscience, Hopkinton, MA, USA) and BOND Rxm automated stainer (Leica Biosystems; Wetzlar, Germany) using the following antibodies; anti-pan-cytokeratin (CK) (rabbit poly; Bioss, Woburn, MA, USA), anti-CD4 (EPR19514; Abcam, Cambridge, UK), anti-CD8α (EPR20305; Abcam) and anti-Foxp3 (1054C; Novus Biologicals, Centennial, CO).
The slides were imaged in the Mantra Quantitative Pathology Workstation (PerkinElmer, Waltham, MA) and analyzed with inForm Cell Analysis software (PerkinElmer).