CD8A and cancer: To validate these stromal and immune reaction markers of GBCs, we performed immunostaining for vimentin, CD8, and T-cell immunoglobulin mucin-3 (TIM-3) on 35 formalin-fixed paraffin-embedded (FFPE) GBC slides obtained from the same patients and compared the expression of markers between Clusters A and B. Vimentin is a marker of mesenchymal-derived cells and cancer-associated fibroblasts (CAFs), which involve a cancer stromal component and TME [17].