1. A method involving a correlation value determining and visualization system, the method comprising: (a) segmenting a digital image of a tissue slice of a cancer patient into first image objects representing immune cells and second image objects representing cancer cells, wherein the tissue slice was stained with a first antibody that is specific to a first protein present in immune cells, and wherein the tissue slice was stained with a second antibody that is specific to a second protein present in cancer cells; (b) identifying a reference correlation value; (c) identifying an image region in the digital image, wherein the image region is divided into a set of tiles; (d) generating, for each tile, a first value and a second value, wherein the first value is indicative of a density of the first image objects in the tile, and wherein the second value is indicative of a density of the second image objects in the tile; (e) determining, for the image region, a measured correlation value of the first value with respect to the second value; (f) comparing the measured correlation value determined in (e) with the reference correlation value identified in (b) and thereby generating a correspondence value; and (g) displaying the image region on a display of the system along with an associated visual indication representing the correspondence value determined in (f), wherein (a) through (g) are performed by the system.