Fig. 1.

Immune phenotype turns “cold” in matched distant metastases irrespective of molecular subtype. Whole breast cancer tissue sections were stained for CD8, PD-1, and LAG-3 (a). CD8⁺ T cells were scored semiquantitatively and assigned to the proposed immune phenotype (b). Based on the CD8⁺ T cell distribution pattern within the tumor compartments, the samples were classified into “hot”/inflamed or “cold”/excluded/desert tumors (c). An alluvial plot [24] was used to depict the distribution of immune phenotypes within the primary tumor (left) and the corresponding distant metastases (right) among the molecular breast cancer subtypes (middle). Metastases turned into “cold” tumors irrespective of the molecular subtype (d)