FIGURE 4.

Primary and recurrent tumors exhibit differential cell‐cell spatial relationships between tumor cells and T_REG. A, B, Spatial relationships between pCK⁺ tumor cells and immune cells are compared between new primary (A) and recurrent primary (B) head and neck tumors from the same individual. CD3⁺CD4⁺Foxp3⁺ regulatory T cells (T_REG) exhibited short proximity to tumor cell nests at recurrent status. Scale bars, 100 μm. C, Cell‐cell spatial relationships between tumor cells and T_REG were quantitatively assessed via pair correlation function analysis. The values were < 1.0, indicating a mutually exclusive distribution between tumor cells and T_REG at the primary tumors