RT Journal Article SR Electronic T1 Endogenous 4β-Hydroxycholesterol-to-Cholesterol Ratio Is Not a Validated Biomarker for the Assessment of CYP3A Activity JF Drug Metabolism and Disposition JO Drug Metab Dispos FD American Society for Pharmacology and Experimental Therapeutics SP 1972 OP 1972 DO 10.1124/dmd.113.054361 VO 41 IS 11 A1 Joseph D. Ma A1 Anne N. Nafziger A1 Joseph S. Bertino, Jr. YR 2013 UL http://dmd.aspetjournals.org/content/41/11/1972.abstract AB