“…Although CYP3A4 is genetically polymorphic, no clear link between genotype and variability in enzyme activity has been reported yet. On the other hand, CYP3A5 genotype is the most important contributor to inter‐individual differences in CYP3A‐dependent drug disposition particularly in black African populations (Diczfalusy et al, 2008 ; Gebeyehu et al, 2011 ; Mukonzo, Waako, Ogwal‐Okeng, Gustafsson, & Aklillu, 2010 ; Mutagonda et al, 2019 ). We previously reported a significant influence of sex on CYP3A activity in healthy Ethiopian volunteers using the 4β‐OHC/Chol ratio as a marker (Gebeyehu et al, 2011 ) and also in healthy Ugandans using quinine as a CYP3A probe drug (Mukonzo, Waako, Ogwal‐Okeng, Gustafsson, & Aklillu, 2010 ).…”