Unlike DataNodes Labels in WikiPathways GPML pathways do not have semantic knowledge, because of the lack
of a linked identifier. Interactions are used to link two DataNodes. Labels should be linked with
graphical lines.
The Interaction links to a Label.
There are two possible solutions to this fail. First, you can convert the Label to which the Interaction
links into a DataNode. Second, you can convert the Interaction into a graphical line.