A horizontal bar is shown for each data category. The width of the bar indicates the number of data points for this category. Move your mouse from the top to the bottom to explore and discover a the connection between receptor type and stored bias type. An example is the path "Peptide -> Opioid receptor -> G Protein -> Gi / beta arrestin" describing ligands that try to avoid beta arrestin activation on the opioid receptor (in August 2019 about 12% of the database).

References:

This visualization is based on Fabian Bendix, Robert Kosara, and Helwig Hauser. Parallel Sets: Visual Analysis of Categorical Data. In IEEE Symposium on Information Visualization (InfoVis), pp. 133–140, 2005 [PDF] as well as on the D3/Javascript implementation by Jason Davies