Implementing SBGN in Cytoscape. Rendering limitations. In picture (a) the reduced amount of node and edge shapes available in Cytoscape to represent all the entities present in the reference cards of SBGN is noticeable. Picture (b) illustrates how the SBGN edge shapes that are not supported in Cytoscape are obtained with CySBGN by an aggregation of supported edges shapes using an auxiliary and invisible node between them. The colour distinguishes the different types of nodes used to obtain the final edge shape. Picture (c) depicts how the random ordering of the nodes may affect the visualization of the diagram.