Fig 2: Comparison of tumor immune microenvironment types between PGC and MGC. (a) Comparison of types based on CD8+ T-cell density and the distribution between PGC and MGC. (b) Representative multiplex IHC images of a PGC specimen with inflamed type (high CD8+ T-cell density in the IT region). (c) Representative multiplex IHC images of paired MGC specimens with immune desert type (low CD8+ T-cell density in the IT, IM, and PS regions). (d) Comparison of types based on T-cell density and PD-L1 expression in the IT and IM regions between PGC and MGC. (e) Representative multiplex IHC images of PGC specimens with adaptive immune resistance type (high CD4+ + CD8+ T-cell density and PD-L1-positive). (f) Representative multiplex IHC images of paired MGC specimens with immunological ignorance type (low CD4+ + CD8+ T-cell density and PD-L1-negative). PGC primary gastric cancer, MGC metastatic gastric cancer, IHC immunohistochemistry, IT intratumoral, IM invasive margin, PS peritumoral stroma, PD-L1 programmed death-ligand 1, CK cytokeratin.

Fig 3: Multiplex immunofluorescent images show the individual antibody staining as follows (×200): (A) CD68+(Opal 620); (B) CD8+(Opal 690); (C) CD20+(Opal 570); (D) CD4+(Opal 540); (E) Foxp3+(Opal 650); (F) Antibody staining was merged with cytokeratin (CK, Opal 520) staining. Blue nuclear stain represents 4',6-diamidino-2-phenylindole (DAPI).

Fig 4: Overall survival according to total CD8+ T-cell density in PGC and MGC. PGC primary gastric cancer, MGC metastatic gastric cancer, OS overall survival. Statistical analysis was performed using the Kaplan–Meier method.

Fig 5: The proportions of mononuclear cell subsets for acute TCMR versus BKVAN cases in cortical interstitium. CD8+ cells were significantly more prevalent in TCMR than BKVAN cases (p = 0.034).