Figure 4From: Evaluation of bioactive sphingolipids in 4-HPR-resistant leukemia cells Comparative analysis of dihydroceramide desaturase (DES) activity. Cells were incubated with the unnatural pyridinium dhCer (C12-PyrdhCer) alone or with 4-HPR (5 μM) for the selected time points and conversion into C12-PyrCer measured by LC/MS. Data are average ± SD of two independent values. **P < 0.01; ANOVA plus Bonferroni post-hoc test.Back to article page