fig4

Figure 4. The relative concentration changes in biomarkers of tryptophan (left), carotenoids (middle) and lipids/lipoproteins (right) in the normal skin tissue and BCC skin tissues with depth-dependence. Dramatic changes on relative concentrations are shown for the lesion slices at the depth of 100 µm compared with other depths of 200 µm, 1,100 µm and 1,600 µm. Based on student’s t-test, the difference between normal and BCC samples is statistically significant (P < 0.05) for biomarkers: 752, 1,161 and 1,521 cm^-1. The units of the numbers in the figure legends are cm^-1. BCC: basal cell carcinoma