Figure 2. Effect of a low dose of Selenium on keratinocyte clonogenic potential. (A) Average of the CFE ratio after treatment (KT CFE) versus control KC CFE (KT CFE/KC CFE) obtained after 12 days of Selenium application over a range of concentrations from 6.3 µM to 1.875 nM, and (B) results are expressed as the mean ± SD of 3 donors (n=3). CFE ratios are calculated to avoid inter-individual heterogeneity of CFE. *p<0.05; **p<0.01; ***p<0.001.