APOL1 and focal segmental glomerulosclerosis: Nevertheless, these two G1 and G2 APOL1 gene Vs, in contrast to the wild type (WT) G0 allele, have been shown to associate with several kidney pathologies including hypertension-attributed nephropathy, non-diabetic end-stage kidney disease, and the most strongly focal segmental glomerulosclerosis (FSGS) and HIV-associated nephropathy (HIVAN), an important complication of HIV infection characterized by collapsing FSGS associated to massive proteinuria [7, 8].