CYP2B6 and chronic kidney disease: In humans 71% of the OH‐BUP formation is due to CYP2B6 and multiple studies have reported reductions in conversion of BUP to OH‐BUP in CKD patients.4, 7, 12, 14, 42 To date, no study has assessed the expression of CYP2B6 or the expression and function of rat CYP2B1 and CYP2B2 in CKD.