Untargeted metabolomics aims to measure the whole set of metabolites within a given biological material and to compare the levels of the small molecules present between different conditions, e.g., healthy vs. disease, treated vs. untreated etc., providing potential markers of the situation under study. The novelty of this global approach is that it involves working without a priori hypotheses, often just assuming that the conditions under comparison are different. In order to reach sound conclusions, as many metabolites as possible have to be measured, and advanced statistical analysis has to be performed to reveal those changes that will...