In the molecular interaction map, each named molecule is shown only once. A variety of defined connecting lines serve to describe the interactions between the molecules. A summary of the conventions used to depict binary interactions between molecules is shown below. Multimolecular complexes or modified forms are depicted by "nodes" placed on the lines. A line may originate either at a named molecular species or at a node, and may terminate at a molecular species, a node, or at another line. Lines that cross do no imply an interaction.