Lipid Ontology enrichment analysis
LION/web is a freely available online enrichment analysis tool specifically designed to assess lipidomics data. It's underlying ontology, LION (Lipid Ontology), links over 50,000 lipid species to the LIPIDMAPS classification system, as well as to chemical, biophysical, and cell biological properties. Enrichment of LION terms can be calculated by either comparing subsets of lipids to background lipidomes (e.g., to assess LION-term enrichment of significantly altered lipids) or by evaluating the distribution of LION-terms over a ranked list of lipids (e.g., to compare condition A to B). The tool supports various lipid nomenclature dialects to ease data input. Recently, a new module, LION-PCA heatmap, was added to the web-tool. This module generates a heatmap of the most fluctuating LION-terms for all the samples in a given dataset, thereby providing a comprehensive overview of the dataset in just a few mouse-clicks.