REN and chronic kidney disease: The former include age, gender (in adults), race, cause of CKD, stage of CKD at the beginning of follow-up (CKD progression is logarithmic rather than linear) [5,6,7], or certain genetic polymorphisms, e.g., elements of the renin–angiotensin–aldosterone system or GSTM1 deletion, as revealed in CKiD study [23].