The final graph database contained 16.618 nodes and 34,703 edges, where 2,397 nodes were metabolites and 999 nodes were proteins. The node count also contained 2,204 CHEBI nodes and 1,370 HMDB entries; the remaining nodes were reaction nodes connecting the proteins to their corresponding metabolic conversion(s). Regarding all metabolic conversion data, there were a total of 4,358 reactions, with LIPID MAPS representing 379 reactions, the Reactome collection 2,009, the WikiPathways collection containing 2,615, and the Analysis Collection (combining WikiPathways and Reactome) 4,209; note that there was overlap between several reactions from the individual databases. The full list of side metabolites contained 212 identifiers, and in total 254 edges were relabeled to belong to side reactions. Figure .2 shows the in-and out-degree for the full network and the individual collections (LIPID MAPS, Reactome, and WikiPathways) as Quality Control Measures. These degrees counted how many neighbors a node had (without adding the mapping nodes since these would cause additional in-degrees for many nodes without biological meaning). The in-and out-degree distribution showed a scale-free topology typical for real networks. The minimum path length was 1, and the maximum directed path length was 38 (excluding the reaction nodes). The contribution of different pathways to the final shortest path can be visualized in multiple ways, such as filtering interactions for a name of interest ("pyrimidine", "amino", or a combination thereof) or a pathway identifier ("WP3604", titled: 'biochemical pathways part I').