CYP2C9 and chronic kidney disease: Other researchers(40), studying 59 Caucasian individuals with chronic kidney disease and chronic use of Losartan, found allelic frequencies of the * 2 and * 3 variants of 5% and 6%, respectively, whose presence was directly related to an increase in proteinuria and in the non-reduction of systolic and diastolic blood pressure, confirming the need for studies on the role of the enzyme CYP2C9 and its variants not only in preventing adverse events from antihypertensive therapy with Losartan, as well as its effectiveness in clinical practice.