Fig. 2

(Glucose,Formate) classifier. a Schematic representation of the proposed study design to identify and validate disease metabolite biomarkers considering the prevalence of multiple diseases. Box plots of formate (b) and glucose (c) levels across the healthy controls (H), HER2+ breast cancer (BC), non-small cell lung cancer (LC), severe obesity without diabetes (OD−) and severe obesity with diabetes (OD+) samples. Each point represents a sample, the error bars indicate the range excluding the lowest 5% and highest 5% values, boxes the range excluding the lowest 25% and highest 25% values, and the line within the box the median. Asterisk/double asterisks denote a significant difference of 10⁻³/10⁻⁶ relative to healthy controls (−), two-tailed t test with unequal variance. d, e Volcano plots reporting the statistical significances vs fold change of metabolite levels in the indicated group relative to the healthy controls, in OD+ (d) and OD- (e). Each point represents a metabolite and selected metabolites are indicated by the labels