Cholesterol profile of CHO/NRel-4 cells. Cholesterol profile of NRel-4 cells following 48 hour treatments with PlsEtn precursors (C1, C6-10) and PtdEtn precursors (C4, C5) compared to control CHO cells. A: total cholesterol; B: free cholesterol; C: esterified cholesterol. Cholesterol is reported as μg per million cells. Results are an average of three independent experiments. Asterisk represents values that are significantly different from those observed in DHAPAT-deficient NRel-4 cells (p < 0.05).