Intracellular TTR in SC of human nerve biopsies. A) Representative photomicrographs obtained with confocal microscopy showing colocalization (yellow and orange in merged panel) between TTR (red) and heparan sulfate (green) in sural nerve biopsies from FAP patients. Scale bar 15 μm. B) Representative images from double immunofluorescence between TTR (green) and Oct-6 (red) in sural nerve biopsies from disease control individuals and FAP patients, demonstrating TTR intracellular staining in SC. Superposition of the labels, with DAPI (blue), is shown (merge, n = 4). Scale bar 4 μm. C) Low magnification images from longitudinal sections of human sural nerves showing colocalization between TTR and Oct-6 (arrows); scale bar 40 μm. Chart represents quantification of TTR positive SC, related to total SC in nerve sections. Results are presented as means ± SEM (p* < 0.05).