To upload data to METASPACE centroid mode imzML files were first created using Image Insight Software (Spectroglyph LLC, Kennewick, WA, USA) using a peak intensity threshold of 5. The resulting imzML files were uploaded to METASPACE for further analysis. To compare against similar datasets in METASPACE, the annotation results for all kidney datasets where the matrix is NEDC and organism is either Human or Mouse were downloaded using the METASPACE API for a total of 140 datasets. In all datasets, only on-sample annotations at FDR 10% against HMDB, CoreMetabolome and SwissLipids were considered. In addition, the following two constraints were applied : (1) only annotations detected in at least 2 MALDI-2 datasets were considered, and (2) only annotations detected in at least 10% (14/140) METASPACE datasets were considered for comparison.