APOL1 and focal segmental glomerulosclerosis: Studies in African Americans have found APOL1 risk alleles to be associated with focal and segmental glomerulosclerosis (FSGS) and hypertension-attributed ESKD, proteinuria, impaired renal function, and kidney disease progression, and with more-severe histological abnormalities (glomerulosclerosis, interstitial fibrosis, and tubular atrophy) in those with FSGS or proteinuria [9].