Although APOL1 is highly expressed in the circulation, there is strong evidence that it is the expression of risk variant APOL1 in the kidney that is responsible for the development of CKD (Beckerman et al., 2017; Aghajan et al., 2019; Bruggeman et al., 2014; Reeves-Daniel et al., 2011; Freedman et al., 2016; Freedman et al., 2015). This evidence concerns the gene APOL1 and chronic kidney disease.