Which of the following does heterophilic binding not encompass?

Heterophilic binding involves interactions between different molecules or receptors rather than identical ones. In the context of cell receptors and ligands, this means that heterophilic binding refers specifically to the interaction between different types of molecules, such as a cell receptor engaging with a ligand that is not the same as the receptor itself.

Identical receptors on different cells indicate a homophilic binding scenario, where the same receptors are present on different cells interacting with each other. This does not fit the definition of heterophilic binding, which is strictly about interactions between distinct molecules or receptors. Hence, this option does not fall under the concept of heterophilic binding.

The other scenarios described involve interactions that are characteristic of heterophilic binding. For instance, a receptor binding to a ligand on another cell, receptors connecting through a linker, or binding to ligands that are part of the extracellular matrix all exemplify the principle of heterophilic interactions, as they involve different proteins or structures engaging with one another.