Figure 4

Optical images of a single transverse tissue section following H&E staining (tumor regions defined by black dotted line) for each of the six mouse brains used in the comparative study and the corresponding extracted-ion images for the ten lipids identified in Table 1 shown as 2-dimensional false-color plots. For each m/z values visualized distribution, TIC normalization was applied across all six tumor regions for direct comparison. The extracted-ion images highlight the heterogeneous spatial distribution within each tumor region and also general comparative changes across the six individual tumors.