Figure 3A shows a scatterplot of PC1 and PC6 based on the PCA of data limited to amyloid deposition areas. Although there was a slight overlap, AL (orange dots) and ATTR (green dots) were separated by positive and negative values of PC6, respectively. Figure 3B shows the ROC curve generated to confirm whether AL and ATTR may be discriminated based on the results of the PCA of Raman spectra obtained at amyloidosis deposition areas. This evidence concerns the gene TTR and amyloidosis.