APOL1 and chronic kidney disease: Since mice do not have an ortholog of human APOL1, the Tg26/HIVAN4 mice would represent an APOL1 null phenotype, and mice expressing APOL1-G0 would functionally recreate a human CKD low risk APOL1 genotype, whereas mice expressing APOL1-G2 would functionally recreate a human CKD high risk APOL1 genotype.