Expression of β-catenin and Nanog in EpSCs treated with SP. β-catenin and Nanog were measured at different time points (day 0-day 12) at the mRNA (q-PCR) and protein (western blot) level (A and B). The bands of each protein were quantitatively analyzed (C and D). Both q-PCR and western blot analysis showed that β-catenin expression was significantly higher on or after day 3 than at day 0. Nanog and β-catenin expression had an inverse relationship (*P < 0.05).