Figure 2.

Conceptual illustration of stromal barrier for lymphocytic infiltration. A, Example of the stromal barrier in a region of an H&E slide, where a fibrous stroma can be seen between a lymphoid aggregate and a tumor islet. B, The corresponding TTG, in which cancer cell nodes have been summarized to a cancer supernode, whereas each of the lymphocyte/stromal node represent a single lymphocyte/stromal cell. The number of stromal nodes on the shortest path from a lymphocyte to the nearest cancer supernode was calculated and later averaged to derive the quantitative measure of stromal barrier.