Biomarker analysis. Gene expression profiling in tumor biopsies was examined, and differentially expressed genes evaluated based on best response. (A) Heat map of T cells and M2 macrophage-related genes demonstrating differential gene expression according to best response. Participants who underwent CD8 PET are highlighted by color-coded boxes that correspond to Figure 3D results. (B-D) Expression of T-cell activation score (as described in “Methods”), immune ratio, and TCF7 expression based on best response are represented by panels B, C, and D, respectively. (E) Matched tumor biopsies from baseline (BL), C1D8-15 and progression were evaluated for TCF7 expression (3 CMR in green; 2 PMR in blue; and 7 PD in red). (F-G) Flow cytometry analysis of immune checkpoints (TIGIT and PD-1) and TCF7 was evaluated in CD4⁺ and CD8⁺ T cells at BL and C1D8 (CMR, n = 3; PD, n = 7) for panels F and G, respectively. (H) TCF7 expression was examined in PD1/TIGIT dual-positive cells for CD4⁺ and CD8⁺ cells (CMR, n = 3; PD, n = 7). ∗P < .05; ∗∗P < .01; ∗∗∗P = .009.