linked to several pathways or underlying biochemical mechanisms mentioned in the original study (e.g. 'muscle contraction pathway', 'alanine and aspartate metabolism', 'histidine catabolism', Fig. .3B). Four biomarkers are not depicted: pantothenic acid (Wikidata identifier:Q179894) is part of several pathways, however, cannot be connected through directed shortest path calculations. N-acetyl-arginine was not present in any of the three merged pathway databases. Last, NAD + and NADP + are labeled side metabolites and therefore not part of the visualization.