Figure 4.

Analysis of the levels of PPOX, FECH, and HO-1. (a) Images of stained cells, before and after PDT treatment. (b) Graph with percentage values of corrected total cell fluorescence (CTCF) of untreated, parental cells. (c) Graph with percentage values of corrected total cell fluorescence (CTCF) of CAL-39 cell lines. Asterisks indicate the statistical significance of differences between cells after PDT and untreated control, and between sensitive and resistant cells calculated by Mann–Whitney test (* p ≤ 0.05, ** p ≤ 0.01).